Methods and devices for vascular surgery

ABSTRACT

An anastomotic connector ( 60 ) for attaching two blood vessels, comprising a cylinder-like portion having a lumen, two ends, and an array of cells elements, and a tissue engaging portion ( 60 ) comprising at least one set of spikes ( 64 ) wherein at least one spike arranged adjacent one of the two ends of said cylinder-like portion. The connector ( 60 ) may comprise at least a second set of spikes ( 66 ) adjacent the other of the two ends.

FIELD OF THE INVENTION

The present invention relates to performing an anastomosis andespecially to an anastomosis relating to percutaneous bypass surgery.

BACKGROUND OF THE INVENTION

Connecting two blood vessels, anastomosis, is an important surgicaltechnique for reconstructive, therapeutic and cosmetic surgery. The goldstandard of anastomosis is manual suturing of the two blood vessels in aside-to-side, end-to-end or end-to-side configuration. Although it isgenerally desirable to shorten the length of any surgical procedure,this is especially important in coronary bypass surgery, for exampleminimally invasive procedures in which the heart continues beating andopen surgical procedures in which a patient is often attached to aheart-lung machine and his heart is stopped.

In addition to manual suturing of blood vessels, other methods ofattaching two blood vessels are known, including method using staplesand anastomosis rings. PCT publications WO 97/40754 and WO 97/28749, thedisclosures of which are incorporated herein by reference, describevarious staplers for coronary bypass surgery, wherein a graft isconnected on one of its ends to the aorta and at its other end to anoccluded coronary artery, distal to the occlusion. In this type ofsurgery, the anastomosis is sealed by stapling the graft to the aorta,while pressing both aorta and graft against an anvil. In onepublication, the anvil is inserted into the aorta for the stapling andthen removed, possibly by taking the anvil apart. In the otherpublication, the end of the graft is everted over a ring-shaped anvil,so that the anvil is outside of the blood vessel at all times.

Recently, bypass surgery has been performed using minimally invasive(e.g., key-hole and mini-thoractomy) surgery. In this type of surgery, asmall hole is made in the chest, instead of cracking open the ribs, andthe mammary arteries are used for bypass grafts. The suturing and/orstapling is performed using tools, for example such as those describedabove.

An even less invasive type of surgery requires no opening of the chestat all. Rather, one or more catheters are introduced into the bloodvessels using a percutaneous approach. PCT publications WO 97/27898, WO97/13471 and WO 97/13463 and their priority documents, namely U.S.application 60/010,614, 60/005,164, Ser. Nos. 08/730,327 and 08/730,496,the disclosures of which are incorporated herein by reference and termedthe “Transvascular Applications”, describe methods and apparatus forpercutaneous treatment of arterial occlusions. Two main methods aretaught in these applications. In one method, a tunnel is excavatedwithin tissue (outside the vessel) from one side of the occlusion to theother side of the occlusion, and a stent or a stent/graft is placedwithin the tunnel. In another method, a conveniently located vein orgraft is attached to the occluded vessel and two side-to-sideanastomosis are created between the occluded vessel and the vein orgraft. The distal and proximal portions of the vein are closed in one ofa variety of manners. The connection between the vein and the artery maybe made by welding the two blood vessels, or by using one of a varietyof connectors that are suggested. One of the disclosed connectorscomprises two springs separated by a short segment of a possiblyunstented graft. The springs have the form of an inverted funnel, sothat the two blood vessels are urged together. Where there is a spacingbetween the blood vessels, various techniques and/or devices aresuggested for stopping the surrounding tissue from compressing theconnection between the vein and the artery. One of the purposes of thevarious types of connectors is to maintain the two blood vessels neareach-other, either in contact or compressing tissue between them,presumably so no blood will leak from the connection between theconnector and the blood vessels.

In a TIPS procedure, a stent is placed into a passage percutaneouslyforced, opened or excavated between a portal vein and a hepatic vein. Asin some of the embodiments described in the previous paragraph, therelative location of the blood vessels is maintained by the existence ofrelatively solid tissue surrounding and between the two blood vessels.Thus, there is no requirement that each of the connections between anend of the connector and the respective blood vessel to which it isattached, be, of itself, leak-proof.

In WWW publication“http://me210abc.stanford.edu/94–95/projects/Pfizer/Spring/1.html” (May1998), the disclosure of which is incorporated herein by reference, amethod is described for reducing the complexity of performing a bypasssurgery. In this method, a graft is percutaneously brought to the aortaand pushed out of an incision in the aorta near a site of a bypasssurgery. A keyhole opening is made in the chest to bring a tool tosuture or staple the graft to the aorta and to the coronary which is tobe bypassed.

Hinchliffe in U.S. Pat. No. 5,833,698, the disclosure of which isincorporated herein by reference, describes a multi-pin anastomosisconnector, with or without a ring interconnecting the pins. Alsodescribed is a device, for attaching a graft end to a slit formed in aside blood vessel.

Rygaard in U.S. Pat. No. 5,797,934, the disclosure of which isincorporated herein by reference, describes an end-to side anastomosisdevice that uses a balloon inside the side artery to evert the lips ofan opening in the side artery. The described anastomosis device, whichis provided from outside the artery, includes releasable spikes whichnail the vessels together.

Popov in U.S. Pat. No. 5,702,412, the disclosure of which isincorporated herein by reference, describes a cork-screw like head whichis used to grasp a part of side artery to be punched out. Popov alsodescribes using external clipping devices to apply clips at thecircumference of the anastomosis.

Kaster in U.S. Pat. No. 4,366,819, the disclosure of which isincorporated herein by reference, describes a two part anastomoticdevice for end-to-side anastomosis, using an inner flange and an outerflange. When the flanges are closed an intima-to-intima contact and/oran everted graft can be formed.

PCT publication WO 98/38922, the disclosure of which is incorporatedherein by reference, describes an anastomosis device formed of aflexible cord which can be formed into a loop and which has small spikesformed on it to grasp the blood vessels. Spikes can be bent back usingan anvil inside the blood vessel. This device is also described as beingused for end-to-end anastomosis.

PCT publication WO 98/42262, the disclosure of which is incorporatedherein by reference, describes an anastomosis device that uses aplurality of needles preloaded with sutures.

Gillford in U.S. Pat. No. 5,817,113, the disclosure of which isincorporated herein by reference, describes various types of anastomosisdevices including devices with bending spikes, with or without a ring(inner or outer). In some of the described devices the spikes are benttwice, each time by about 90 degrees. Another described device uses aring which is transfixed by a plurality of hooked wires. These wireshook the “side” vessel, while the ring is connected to an “end” of agraft. When the wires are pulled, the anastomosis is closed.

Kaster in U.S. Pat. No. 5,234,447, the disclosure of which isincorporated herein by reference, describes an anastomosis deviceincluding a ring with long spikes on either side of the ring.

Snow in U.S. Pat. No. 5,797,933, the disclosure of which is incorporatedherein by reference, describes an anastomosis device formed of a thinwire ring with spikes extended to one side of the ring. The ring issomewhat compressed by its having a wave profile. During deployment, thering is straightened, increasing its radius.

Kim in U.S. Pat. Nos. 5,676,670 and 5,797,920, the disclosures of whichare incorporated herein by reference, describe an anastomosis system inwhich a probe is inserted into a side of a blood vessel. The head of theprobe is expanded to allow a mesh shaped anastomosis device to bebrought into the vessel. The head is then further expanded to flattenthe mesh against the inside of the blood vessel. The anastomosis iscompleted by applying a glue on the outside of the anastomosis.

WO 98/38941, WO 98/38942 and WO 98/38939, the disclosures of which areincorporated herein by reference, described ideas for performingtransvascular bypass procedures. In one application a graft is connectedfrom an aorta to an portion of an artery distal to its occlusion. Inanother, such a graft is connected from one of the vessels exiting theaorta. In another, a bypass is created by tunneling through the hearttissue.

SUMMARY OF THE INVENTION

One object of some preferred embodiments of the invention is to provideanastomosis connectors, especially suitable for minimally invasivesurgery.

An object of some preferred embodiments of the invention is to provide aminimally invasive method of bypassing occluded blood vessels,preferably without sacrificing a nearby artery or vein. Typically, agraft is attached between a first blood vessel and a second bloodvessel. In some cases, the graft itself is a blood vessel.

An aspect of some preferred embodiments of the invention relates toanastomotic devices that shrink axially as they expand radially. In apreferred embodiment of the invention, the axial shrinkage and theradial expansion cooperate to perform the anastomosis.

An aspect of some preferred embodiments of the inventions relates toanastomotic devices that extend spikes perpendicularly to a surface of adevice and/or bend such spikes, while the device is being deployed. In apreferred embodiment of the invention, the spike extension is timed sothat the spikes engage both the participating blood vessels.Alternatively or additionally, at least some of the spikes engage onlyone of the blood vessels. However the extension is timed so the spikesengage the vessel at a desired portion thereof.

An aspect of some preferred embodiments of the invention relates toanastomotic devices that exhibit step-type behavior in whichconfiguration changes from one configuration to another are sudden,rather than gradual. In a preferred embodiment of the invention, thisstep-type behavior is used to extend spikes which transfix blood vesselsat a desired location relative to the anastomosis location and/or at adesired timing relative to the anastomosis process.

An aspect of some preferred embodiments of the invention relates to ananastomotic connector including a cylindrical body and one or more setsof spikes. In a preferred embodiment of the invention, the cylindricalbody defines aperture therein, so that tissue on either side of theanastomotic connector can benefit from a significant amount of contactthrough the connector. The spikes are bent to engage the two bloodvessels. In some cases, one set of spikes is bent outside the body andone set of spikes is bent inside the body. In another embodiment, bothsets of spikes are bent or otherwise deformed inside the body. In stillother embodiments all the spikes are deformed only outside the body.When the cylinder is expanded, the two blood vessels are brought intocontact by the expansion, preferably forcefully, so that a betteranastomosis results.

In a preferred embodiment of the invention, the cylinder comprises anarray of parallelograms. Alternatively or additionally, the cylindercomprises a solid surface with slits cut therethrough, perpendicularand/or parallel to the axis of the cylinder. In a preferred embodimentof the invention, the coupling between the two axes (radial and axial)is meditated by the shape and/or other parameters of the parallelograms.

In a preferred embodiment of the invention, the coupling between the twoaxes is dependent on the radius. In one example, when the device is in aradially shrunk configuration, a small radial expansion will produce alarge axial shrink. When the device is in a radially expandedconfiguration, a small additional expansion will only cause a smalladditional axial shrinkage. Alternatively, other relationships betweenshrinkage/expansion of the two axes may be used. The type ofrelationship may be modified by changing the shape and/or aspect ratioof some or all of the parallelograms. In a preferred embodiment of theinvention, the relationship and/or elastic properties and/or otherproperties of the connector are selected for a particular vessel sizebeing connected.

In a preferred embodiment of the invention, an anastomosis that issuspected of leaking may be repaired by radially expanding a connectorof the anastomosis by a small amount, thereby causing axial shrinkageand a stronger contact between the two blood vessels.

Alternatively, a T-shaped stent may be attached over the anastomosisconnector to repair the leak. Alternatively, in some preferredembodiments of the invention, the radial expansion may be decoupled fromthe axial shrinkage, at least for some ranges of radial expansion.

In a preferred embodiment of the invention, the anastomosis connectorcomprises an elastic material. Alternatively or additionally, theconnector comprises a plastic material. In one example, in which spikesare plastically bent to engage the blood vessels, the cylinder comprisesa super elastic, elastic or shape-memory material having an expandedresting position.

In a preferred embodiment of the invention, the connector comprisessteel and/or other non-absorbable materials. Alternatively oradditionally, the connector comprises bio-absorbable materials, so thatafter a period of time, no foreign materials will remain in the body. Inone preferred embodiment of the invention, at least the spikes and/orother portions of the connector which are in contact with the blood areformed of a bio-absorbable material. Preferably, the bio-absorbablematerial is molded and/or crimped on non-bio-absorbable materials.Examples of possible bio-absorbable materials include poly-l-lactid-acidand poly-glycolid-acid, which can both be formed with elasticproperties.

In a preferred embodiment of the invention, a connector having a similartype of coupling between radial expansion and axial contraction is usedto attach two blood vessels with end-to-end or end-to-side anastomoticconnections. Alternatively or additionally, a device with a similarconfiguration may be used to secure a valve in a blood vessel, such asthe aorta or a vein. When the device is inflated, the spikes dig intothe blood vessel to hold the valve in place. In these types ofconnection, axial compression is preferably minimal or non-existent. Thedevice itself may be inserted over an existing valve, whereby the spikesand/or the cylindrical body may be used to compress the old valveagainst the walls of the blood vessel. Alternatively, the old valve maybe cut out, in part or in full using a suitable catheter. In a preferredembodiment of the invention, the valve is inserted while the heart ispumping. The valve is preferably a soft leaflet valve.

In a preferred embodiment of the invention, the anastomosis connector isused for externally performed anastomotic connections, preferablykeyhole surgery, instead of for an anastomosis performed from inside theblood vessel. In a preferred embodiment of the invention, two bloodvessel ends are inserted into or over an anastomosis device while thedevice is in a compressed condition. The device is then inflated.Preferably the device comprises an elastic shape-memory or asuper-elastic material so that it may be expanded by releasing aconstraining ring or holder.

An aspect of some preferred embodiments of the invention relates tosimultaneously attaching two blood vessels and increasing the size of apassageway between them. Preferably, such expansion is made possibleusing an inflatable balloon. Alternatively, a different type ofexpanding framework may be used, for example, a super-elastic, elasticor shape-memory framework which expands when a constraint is removed ora hinged construction in which pulling a wire causes the construction toincrease at least one dimension thereof.

An aspect of some preferred embodiments of the invention relates to aclotting control coatings on an implantable device, for exampleanastomotic connectors, blood vessel patches, staples, threads andgrafts (on their outside). In a preferred embodiment of the invention,the anastomotic device includes one or more of the following three typesof portions: (a) a contact portion which is in contact with the bloodstream; (b) a layered portion which is sandwiched between the twoparticipating blood vessels; and (c) an outside portion which is outsideboth the blood vessels. In a preferred embodiment of the invention, aclot retarding material is coated on the contact portion of theanastomosis device. Alternatively or additionally, a clot enhancingmaterial is coated on the layered and/or outside portions of the device.Alternatively or additionally, tissue growth enhancing hormones arecoated on the layered and/or outside portions of the device. In somepreferred embodiments of the invention, even though the anastomoticdevice is provided through a blood vessel, once it is deployed, it is inminimal or no contact with the blood flow. Preferably, less than 70%,80%, 90% or even 98% of the surface of the anastomotic device is out ofcontact with the blood flow. This selective coating logic of ananastomosis device may also be applied to other implantable devices.Often, in implantable devices, one part of the device is in contact withblood and one is not. the side that is not in contact with blood ispreferably treated to coagulate any blood it may come in contact with(for example as a result of a failure of the anastomosis device).Alternatively or additionally, the implant may be coated with a fibrosisinducing coating, for example a graft thus coated will better adhere toadjacent body structures. A surgical staple may have its tines coatedwith one material and its base with another. A thread may be coated inpart with an anti-coagulation coating, for example during insertion intoa blood vessel, and in part with a coagulation enhancing coating (forexample a coating embedded in the thread or applied when the threadexits the blood vessel. Such coatings can be applied by a needle guidingelement which is used in some anastomotic methods of the art.

An aspect of some preferred embodiments of the invention relates to ananastomotic connector which is partly super elastic, elastic and/orshape-memory and partly not. In a preferred embodiment of the invention,the connector is formed of a single material, which is then annealed atportions thereof to make those portions non super-elastic.Alternatively, a device is created from sintered material. The sinteredmaterial may have varying concentrations of constituent powered metalsin different parts of the mold. In a preferred embodiment of theinvention, the mold is for a tube and the tube is then cut, for exampleusing a laser or using a water jet. In a preferred embodiment of theinvention, the variations in material composition are radial and/oraxial.

An aspect of some preferred embodiments of the invention relates toexpandable anastomotic devices. In a preferred embodiment of theinvention, the device can be radially and/or axially compressed so thatit can be fit inside a blood vessel and/or a small aperture in a bloodvessel. In some cases the device is provided through a patent bloodvessel. In others, the device is provided from outside the a bloodvessel to which it is later connected. In some cases, the graft and/orthe connector are provided through the blood vessel, exposed to theblood flow. In a preferred embodiment of the invention, at least one ofthe anastomosis connectors has a shape which can be changed. This canmake it easier to guide such a graft through a catheter and/or endoscopelumen. Preferably, the graft maintains a radially compressedconfiguration due to the radial compression of anastomotic connectorsattached to the graft. Alternatively or additionally, the connectors aremaintained radially compressed by an internal guide wire which restrainsthem from expanding. Alternatively or additionally, the connectors areplastically deformable. Preferably, the shape changing comprises radialshape changing, preferably expansion. Alternatively or additionally,especially where the connector is connected to the graft at a “side”side of the anastomosis, the connector is preferably compressed in aradial direction, so that in its compressed shape at least one radiithereof fits in a desired lumen diameter.

In a preferred embodiment of the invention, a blood vessel graft isbrought through the vasculature to a location on a blood vessel and anindependent and patent anastomosis between the graft and the bloodvessel is formed. By “independent” it is meant that the anastomosislocation does not leak, regardless of whether or not the other end isconnected. In a preferred embodiment of the invention, the anastomosisis an end-to-side anastomosis, preferably the end being an end of thegraft. Alternatively, the anastomosis is an end-to-end, side to side oroblique anastomosis. In a preferred embodiment of the invention, theblood vessel is an Aorta. Alternatively or additionally, the graft is axenograft or formed of an artificial material.

In a preferred embodiment of the invention, the other end of the graftis also attached, via at least one additional anastomosis to a secondblood vessel, preferably other than the first blood vessel. In apreferred embodiment of the invention, the graft is connected to aplurality of blood vessels, preferably using a plurality of side-to sideanastomosis connections along its length. Alternatively or additionally,the graft is forked or otherwise has more than two ends each of which ispreferably attached to different blood vessels or different positions onthe same blood vessel.

Some features of preferred embodiments of the present invention relateto the first anastomosis connection (to the first vessel), while otherfeatures relate to the second anastomosis connection (to the secondvessel). Many of the features can be applied to either or both of theconnections.

An aspect of some preferred embodiments of the invention relates to agraft having attached thereto at least three independent anastomosisconnectors. Preferably, at least one of the connectors is attached at anend of the graft. Alternatively or additionally, at least one of theconnectors is a side-to-side or side-to-end connector where the graft isa “side” element in the anastomosis.

In a preferred embodiment of the invention, at least one of theanastomotic connectors comprises an everting connector, such that atleast one side of the anastomosis, e.g., the graft, is everted over theconnector. In some cases, both sides of the anastomosis are at leastpartially everted with the aid of the anastomotic connector.

In a preferred embodiment of the invention, these second anastomosisconnections are performed percutaneously. Alternatively or additionally,these anastomotic connections are performed using key-hole surgery. Inone preferred embodiment of the invention, the graft is a patch to beapplied to the outside and/or inside of the blood vessel, rather thanbeing a blood carrying vessel of itself. Thus, only one end of the graftis ever connected to a blood vessel.

An aspect of some preferred embodiments of the invention relates tomethods and apparatus for creating a vessel aperture in a “side” of aside-to-end or a side-to side anastomosis. In a preferred embodiment ofthe invention, a small hole is formed and/or punched in the side bloodvessel. Then, the hole is expanded so that an anastomotic connector maybe inserted into the hole. Thereafter, the hole may be further enlarged,possibly by a radial force exerted by the anastomotic connector or by adevice which expands the connector. In a preferred embodiment of theinvention, the side vessel is elastically encouraged to reduce thediameter of the hole, thereby providing pressure against the end vessel,so that little or no blood leaks out of the anastomotic joint. In apreferred embodiment of the invention, the anastomosis is thus complete,except for a means for maintaining the end vessel at a minimum radiusand inside the hole. Preferably, that means is provided by theanastomotic connector itself. In some preferred embodiments of theinvention, the original hole is formed using a vibrating and/or rotatinghead.

In a preferred embodiment of the invention, the hole is formed in ablood vessel from inside the blood vessel. Preferably, a catheter with ahole forming mechanism at its end is bent 90 degrees, so that the end isperpendicular to the wall of the blood vessel. Possibly, the bend in thecatheter rests against the blood vessel wall opposite the hole beingformed. Alternatively or additionally, the catheter is provided with anincreased stiffness so that less force is applied against the restingpoint on the blood vessel wall. Alternatively or additionally, the endmechanism grasps the wall of the blood vessel in which the aperture isformed so that little or no contra-force is required. For example, themechanism can include a clamp and/or a suction tip for maintaining thewall of a blood vessel in a desired position while pushing a sharp guidewire tip through it. Alternatively or additionally to 90 degreeconnections into and out of blood vessels, at least one of theinsertions is performed at an oblique angle to the vessel wall, forexample, less than 80, less than 60, less than 40 or even less than 20degrees. Alternatively or additionally, the final angle of the graft tothe vessel is also oblique, for example, at these angles.

When the guide wire is pushed out of the opening made in the first bloodvessel the graft is preferably brought out of the blood vessel along theguide wire. Preferably, the anastomotic device remains “stuck” in theopening in the first blood vessel. A balloon is preferably brought alongthe guide wire into the anastomosis connector and expanded. In somepreferred embodiments of the invention, the anastomosis connector istopologically external to the blood vessel, however, due to folding ofthe vessels, it occupies space inside one or both the blood vessels andthe graft. Preferably the anastomosis connector exits the first bloodvessel when the anastomosis is completed so that it mostly external tothe graft and the blood vessel. In some cases, the connector may have tobe pushed out of the blood vessel.

In a preferred embodiment of the invention, the free end of the graft isnavigated in the body until it is adjacent to a second blood vessel, ata desired location thereof. Preferably, this navigation is facilitatedby an ultrasound imager and/or Doppler sensor, coupled to a guide wireor a catheter on which the graft is carried. Preferably, the sensor issituated outside of the graft, so that it can better sense itssurroundings. Possibly, the graft is enclosed in an endoscope.Alternatively, the graft encloses an endoscope. In some cases, the firstanastomosis is also performed after such guiding, for example if thegraft is brought in to the chest cavity using key-hole surgicaltechniques.

An aspect of some preferred embodiments of the invention relates to theanastomosis of the graft to a blood vessel, after such navigation. Aguide wire, possible the same guide wire as used for a first connection,is inserted into the second blood vessel, to create a hole in thevessel. The insertion may be done by simply pushing the guide wire intothe vessel wall. Preferably, the guide wire is inserted into the secondvessel for a considerable length. Optionally, the guide wire is bentand/or barbed so that it will not retract from the second vessel.Alternatively, a screw-tip guide wire may be used to screw the guidewire tip into the wall of the second blood vessel. The graft and thesecond anastomosis connector are brought along the guide wire andinserted into the hole in the second blood vessel, from inside the firstblood vessel. Preferably, the attachment is by pushing the end of thegraft, preferably with an anastomosis connector attached thereto, into asmall hole in the target blood vessel and increasing the diameter of theanastomosis. A balloon is preferably brought along the guide wire toinflate the anastomosis connector and/or widen the opening in the secondblood vessel. In a preferred embodiment of the invention, a suctiondevice, for attaching to a moving organ such as the heart, is provide ator near the end of the graft, to steady the graft relative to movementsof the heart.

Alternatively to using a balloon to inflate the connector, ananastomosis connector may comprise a super elastic material. In thiscase, the anastomosis connector is preferably maintained in a compressedposition by an enclosing element. Once the connector is in place, theenclosing element is removed and the connector expands to a desiredshape. The term “super elastic” is used herein to denote a materialwhich returns to a desired shape when a restraint is removed. In somecases, an elastic material may suffice. Alternatively or additionally, ashape memory alloy may be used and activated to return to the learnedshape.

Alternatively or additionally to using a guide wire to make a pinholeand expanding the hole using an expandable anastomosis connector, a holepuncher (for example as described in the Background of the Invention)may be provided along the guide wire to cut out a portion of one or boththe blood vessels. Alternatively or additionally, a slit or an x-shapedcut in the vessel wall may be made by the guide-wire.

In a preferred embodiment of the invention, the graft vessel isreinforced, on its inside and/or on its outside and/or in its body.Preferably, the reinforcing is along its entire length. Alternatively oradditionally, only portions of the graft are reinforced, such as itsends or its middle. In a preferred embodiment of the invention, thereinforcing provides radial stiffness. Alternatively or additionally,the reinforcing provides axial stiffness. In a preferred embodiment ofthe invention, the type and/or degree of stiffness provided varies alongthe graft. In a preferred embodiment of the invention, the stiffness issymmetrical around the axis of the graft. Alternatively or additionally,the stiffness is asymmetrical, for example, if one side of the graft isto be in contact with the heart, that side may be made stiffer. In apreferred embodiment of the invention, an external spring is attached tothe graft so that if the graft is too long, it will spiral gracefully,in a desired manner, rather than kink.

Many types of grafts and/or reinforced grafts are known in the art andthey are generally all suitable for use in various embodiments of thepresent invention.

An aspect of some preferred embodiments of the invention relates to amethod of attaching the anastomosis connector to the graft, prior toinserting the graft into the body. In a preferred embodiment of theinvention, the anastomosis connector is covered with a flap of graftmaterial and the covered connector is attached to the graft, such thatthe anastomosis is made via the flap. Preferably, the graft flap isglued to the graft. Alternatively or additionally, the anastomosisconnector and/or the graft flap are sutured to the graft or otherwiseconnected, for example using short spikes. It should be appreciated thatthe graft flap may comprise a different material from the graft. Forexample, the flap may be Dacron and the graft may be a human bloodvessel. In a preferred embodiment of the invention, the anastomosisconnector is provided pre-attached to the flap, which flap is attachedto the graft prior to the graft being inserted, either before or afterthe connector is attached to the flap. Alternatively, the flap isattached to the connector just before the graft is inserted into thebody. In a preferred embodiment of the invention, an end of the graft iscut off and used as a flap for the anastomosis connector.

An aspect of some preferred embodiment of the invention relates to ananastomosis connector comprising two portions, which may be connected orseparate. When the two portions of the connector are attached to eachother to perform the anastomosis there is a reduced requirement to alignthe portions, at least with respect to their rotation around the graftaxis, than with prior art devices. In a preferred embodiment of theinvention, the anastomosis connector comprises two rings, one includingconnection spikes and the other comprising a friction material. When theanastomosis is performed, the spikes are imbedded into the frictionmaterial. Preferably, each one of the spikes passes through one or bothof the blood vessels. Preferably, one or both of the rings may includeeversion spikes, on which to evert the blood vessel. Alternatively oradditionally, the connection spikes are used for eversion.

Alternatively or additionally, the two rings both include spikes andfriction material. Alternatively or additionally, the two rings comprisea rigid material, such that some of the spikes in one ring matchpre-defined holes in the other ring. In a preferred embodiment of theinvention, the anastomosis connector is similar to a Nakayama ringanastomosis device, except that the rings are expandable in the presentdevice. Preferably, the rings are expanded prior to their beingconnected to each other. Alternatively or additionally, the rings areexpanded while being connected to each other. Preferably, the ringsinclude a protrusion and/or a depression so that they can both bealigned, for example, using the guide wire or using a balloon with aguiding groove. Alternatively or additionally, the rings have anotherwise non-circular cross-section.

An aspect of some preferred embodiments of the invention relate to akit, including measuring devices for determining the diameter of agraft, a set of anastomosis connectors having different properties and adelivery system for attaching the graft. Preferably, the kit includes adevice for everting the graft over an anastomosis connector.

An aspect of some preferred embodiments of the invention relates to adevice for punching holes in a blood vessel, form inside the bloodvessel or from outside the blood vessel, where no blood leaks throughthe punched hole. In a preferred embodiment of the invention, a formedtip is pushed through a wall of the blood vessel and then an outer tubeis pushed out over the tip, such that a portion of the vessel wall iscaptured between the tube and the tip and cut off. Leaking is preferablyprevented by the pressure of the wall against the outer tube.

There is thus provided in accordance with a preferred embodiment of theinvention, an anastomotic connector for attaching two blood vessels,comprising:

-   -   a cylinder-like portion defining a lumen, having two ends and        comprising an array of cells-elements; and    -   a tissue engaging portion comprising at least one set of spikes        comprising at least one spike arranged adjacent one of the two        ends of said cylinder-like portion.

Preferably, said connector comprises at least a second set of spikesadjacent the other of the two ends.

There is also provided in accordance with a preferred embodiment of theinvention, an anastomotic connector for attaching two blood vessels,comprising:

-   -   a cylinder-like portion defining a lumen; and    -   a plurality of tissue engaging portions for engaging two blood        vessels, said plurality comprising at least one spike,    -   where radial expansion of said cylinder-like portion causes said        at least one spike to engage tissue. Preferably, radial        expansion of said cylinder-like portion is de-coupled from axial        contraction of said cylinder-like portion.

There is also provided in accordance with a preferred embodiment of theinvention, an anastomotic connector for attaching two blood vessels,comprising:

-   -   a cylinder-like portion defining a lumen; and    -   a plurality of tissue engaging portions for engaging two blood        vessels,    -   where radial expansion of said cylinder-like portion is coupled        to axial contraction of said cylinder-like portion. Preferably,        at a maximum radial expansion, a ratio between axial contraction        and radial expansion is more than about 1:10. Alternatively, at        a maximum radial expansion, a ratio between axial contraction        and radial expansion is between than about 1:10 and 1:5.        Alternatively, at a maximum radial expansion, a ratio between        axial contraction and radial expansion is between than about 1:5        and 1:2. Alternatively, at a maximum radial expansion, a ratio        between axial contraction and radial expansion is between than        about 1:2 and 1:1. Alternatively, at a maximum radial expansion,        a ratio between axial contraction and radial expansion is        between than about 1:1 and 2:1. Alternatively, at a maximum        radial expansion, a ratio between axial contraction and radial        expansion is between than about 2:1 and 4:1. Alternatively, at a        maximum radial expansion, a ratio between axial contraction and        radial expansion is less than about 4:1.

In a preferred embodiment of the invention, said radial expansionactivates at least one of said tissue engaging portions. Alternativelyor additionally, at least one of said tissue engaging portions comprisesat least one spike.

In a preferred embodiment of the invention, said cylinder-like portioncomprises a plurality of cell elements. Alternatively or additionally,said cylinder-like portion comprises a plurality of cell elements.

In a preferred embodiment of the invention, said at least one spike isarranged to extend out of said lumen when said tissue engaging portionsengage tissue in a completed anastomosis. Preferably, said extendedspike lies in a plane tangent to said cylinder-like portion.Alternatively or additionally, said extended spike lies in a planeperpendicular to said cylinder-like portion.

In a preferred embodiment of the invention, said at least one spike isarranged to extend into said lumen when said tissue engaging portionsengage tissue in a completed anastomosis. Alternatively or additionally,said device is arranged to cantilever said at least one spike into anextended configuration by an expansion of said cylinder-like portion.Alternatively or additionally, said device is arranged to release saidat least one spike to assume an extended configuration by an expansionof said cylinder-like portion. Alternatively or additionally, a portionof said cylinder-like portion is arranged to deform into said at leastone spike, by an expansion of said cylinder-like portion. Alternativelyor additionally, said spike is pre-stressed to lie outside of an axialprofile of said cylinder-like portion. Alternatively or additionally,said spike is coupled to a base, and pivotally connected to saidcylinder-like portion and where said base extends into said lumen.Alternatively or additionally, said cylinder-like portion includes aplurality of weakenings, such that plastically deforming saidcylinder-like portion will extend said spikes to engage said tissue.

Alternatively or additionally, said cylinder-like portion comprises abi-stable cell, which cell extends said spike in one state and not inthe other one of said states. Alternatively or additionally, saidcylinder-like portion is arranged to twist, in at least one locationthereon, which location is coupled to said at least one spike, wherebysaid twist causes said spike to extend. Alternatively or additionally,said spike comprises a protrusion to prevent engaged tissue fromslipping off said spike. Alternatively or additionally, said spikecomprises a protrusion to prevent engaged tissue from slipping alongsaid spike beyond said protrusion. Alternatively or additionally, saidspike is arranged to bend at least 90° when it extends. Alternatively oradditionally, said spike is arranged to bend at least 150° when itextends. Alternatively or additionally, said spike is arranged to bendat least 180° when it extends. Alternatively or additionally, said spikeis arranged to bend at least 210° when it extends. Alternatively oradditionally, said spike is arranged to bend at one point thereon whenit extends.

Alternatively or additionally, said spike is arranged to bend at atleast two points thereon when it extends. Alternatively or additionally,said spike is arranged to bend in a continuous curve when it extends.Alternatively or additionally, said spike is arranged to engages saidtissue when it is axially retracted relative to the cylinder-likeportion. Preferably, said at least one spike comprises a plurality ofspikes and where each of said spikes is independently retractable.

In a preferred embodiment of the invention, said at least one spikecomprises at least two spikes and said connector comprises at least asecond spike and said second spike is arranged to bend towards said atleast one spike and said at least one spike is arranged to bend towardsat least a second spike. Preferably, spikes of said at least a secondspike are arranged in a radially staggered configuration relative tosaid at least two spikes.

In a preferred embodiment of the invention, said at least one spike isassociated with an individual flat coil spring. Alternatively oradditionally, said at least one spike is associated with an axial cellelement, which cell element selectively retracts or extends said spike.

In a preferred embodiment of the invention, spikes of said at least asecond spike are arranged to be in a same plane as spikes of said atleast one spike, when the spikes are in a bent configuration.

In a preferred embodiment of the invention, said lumen has an ellipticalcross-section. Alternatively, said lumen has a circular cross-section.Alternatively or additionally, said lumen has a polygonal cross-section.Alternatively or additionally, said lumen has fixed inner diameter.

Alternatively, said lumen has a varying inner diameter. Preferably, saidinner diameter has an hourglass profile, being flared at the ends of thelumen. Alternatively, said lumen is flared at one end of the lumen.

In a preferred embodiment of the invention, a cross-section of saidlumen varies along said lumen. Alternatively or additionally, said lumenis matched to a coronary vessel. Preferably, said matching includesmatching a degree of obliqueness of the lumen cross-section.

In a preferred embodiment of the invention, at least one of said cellelements has parallelogram geometry. Alternatively or additionally, atleast one of said cell elements has an elliptical geometry.Alternatively or additionally, at least one of said cell elementscomprises a ratchet for maintaining said cell element in a distortedconfiguration, once such a configuration is achieved. Alternatively oradditionally, at least one of said cell elements is arranged to distortout of a plane of said cell, when that cell is expanded along a certainaxis thereof. Alternatively or additionally, at least one of said cellelements comprises an outline geometrical shape. Alternatively at leastone of said cell elements comprises a substantially full geometricalshape.

In a preferred embodiment of the invention, at least one of said cellelements is planar. Alternatively or additionally, at least one of saidcell elements is not planar. Alternatively or additionally, said cellsare arranged as bands on at least a portion of said cylinder-likeportion, each of said bands comprising substantially a single type ofparallelogram. Preferably, said bands are axial bands. Alternatively oradditionally, said bands are circumferential bands.

In a preferred embodiment of the invention, substantially all of saidcylinder-like portions is composed of cell-elements. Alternatively oradditionally, said cell elements meet at junctions and the devicecomprises at least one substantially rigid strut interconnecting atleast two junctions. Alternatively or additionally, said cell elementsmeet at junctions and the device comprises at least one substantiallyflexible wire interconnecting at least two junctions. Alternatively oradditionally, said cylinder-like portion comprises several cell typesand where said cell types are uniformly distributed on saidcylinder-like portion.

In a preferred embodiment of the invention, said cylinder-like portioncomprises several cell types and said cell types are non-uniformlydistributed on said cylinder-like portion. Preferably, said distributionis symmetric. Alternatively, said distribution is asymmetric.

In a preferred embodiment of the invention, the device comprises one ormore pressure protrusions on said cylinder-like portion, where said oneor more pressure protrusions are arranged to increase a contact pressurebetween said two blood vessel when said device is deployed.

In a preferred embodiment of the invention, said cylinder-like portioncomprises at least one part which is plastically deformable at a forcewhich does not deform other parts of said portion. Preferably, at leastone of said other parts reacts elastically at said force. Alternativelyor additionally, said part includes weakenings which guide the plasticdistortion of said part.

In a preferred embodiment of the invention, said cylinder-like portioncomprises at least one part which is super-elastic. Alternatively oradditionally, said cylinder-like portion comprises at least one partwhich comprises a temperature-triggered shape-memory material.Alternatively or additionally, said cylinder-like portion comprises atleast one part which comprises a temperature-responsive bi-materialcomposite, which changes its geometry under the effect of smalltemperature changes. Alternatively or additionally, at least one oftissue engagers comprises at least one part which is plasticallydeformable at a force which does not deform other parts of said tissueengagers. Preferably, at least one of said other parts reactselastically at said force. Alternatively or additionally, said partincludes weakenings which guide the plastic distortion of said part.

In a preferred embodiment of the invention, said at least one of tissueengagers comprises at least one part which is super-elastic.Alternatively or additionally, said at least one of tissue engagerscomprises at least one part which comprises a temperature-triggeredshape-memory material.

In a preferred embodiment of the invention, said anastomotic connectoris adapted to engage a side of one of said vessels and an end of anotherof said vessels, to perform a side-to-end anastomosis. Preferably, saidanastomosis is sealed by radial pressure exerted by said cylinder-likeportion and where said tissue engagers maintain the cylinder-likeportion in its position. Alternatively or additionally, said tissueengagers maintain the relative positions of the two blood vessels.Alternatively or additionally, said tissue-engaging portions arearranged on said cylinder-like portion such that when the anastomosis iscomplete, the cylinder like portion is at a certain angle perpendicularto the “side” vessel. Preferably, said certain angle is between about70° and about 90°. Alternatively, said certain angle is between about50° and about 70°. Alternatively, said certain angle is less than about50°.

In a preferred embodiment of the invention, a cross-section of saidlumen is matched to said certain angle.

In a preferred embodiment of the invention, said anastomotic connectoris adapted to engage an end of one of said vessels and an end of anotherof said vessels, to perform an end-to-end anastomosis. Preferably, saidconnector is adapted to be implanted outside of a vascular system.

In a preferred embodiment of the invention, said anastomotic connectoris adapted to engage a side of one of said vessels and a side of anotherof said vessels, to perform a side-to-side anastomosis. Preferably, saidconnector is adapted to be implanted outside of a vascular system.

In a preferred embodiment of the invention, said device is composed, atleast in part, of a bio-absorbable material. Alternatively oradditionally, said cylinder-like portion is composed wholly of abio-absorbable material. Alternatively or additionally, at least one ofsaid tissue engaging portions is composed wholly of a bio-absorbablematerial.

In a preferred embodiment of the invention, at least one of said tissueengagers is adapted to engage an everted graft. Alternatively oradditionally, at least one of said tissue engagers is adapted to engagea non-everted graft. Alternatively or additionally, at least one of saidtissue engagers is adapted to both an everted and a non-everted graft.

In a preferred embodiment of the invention, all of said tissue engagersare adapted to engage said blood vessels inside a body.

In a preferred embodiment of the invention, said cylinder-like portionhas an axial dimension of about 0.5 millimeters. Alternatively, saidcylinder-like portion has an axial dimension of between about 0.5millimeters and 2 millimeters. Alternatively, said cylinder-like portionhas an axial dimension of between about 2 millimeters and 5 millimeters.Alternatively, said cylinder-like portion has an axial dimension ofbetween about 5 millimeters and 8 millimeters.

In a preferred embodiment of the invention, said cylinder-like portionhas a ratio of about 1:1 between its axial dimension and its diameter.alternatively, said cylinder-like portion has a ratio of between about1:1 and about 1:2 between its axial dimension and its diameter.Alternatively, said cylinder-like portion has a ratio of between about1:2 about 1:4 between its axial dimension and its diameter.Alternatively, said cylinder-like portion has a ratio of between about1:4 about 1:8 between its axial dimension and its diameter.

In a preferred embodiment of the invention, said cylinder-like portionis arranged to expand radially by a factor of less than about 1.5.Alternatively, said cylinder-like portion is arranged to expand radiallyby a factor of between 2 and 4. Alternatively, said cylinder-likeportion is arranged to expand radially by a factor of between 4 and 8.

There is also provided in accordance with a preferred embodiment of theinvention, an anastomotic connector for attaching two blood vessels,comprising:

-   -   a cylinder-like portion defining a lumen; and    -   a plurality of tissue engaging portions for engaging the blood        vessels, said plurality comprising at least two spikes,    -   where said two spikes extend differently to engage said tissue.        Preferably, said spikes bend differently. Alternatively or        additionally, said spikes engage the same blood vessel.        Alternatively, said spikes engage different blood vessels.

In a preferred embodiment of the invention, said two spikes are arrangedto extend simultaneously. Alternatively, said two spikes are arranged toextend sequentially. Alternatively, said two spikes are arranged toextend semi-sequentially, such that there is an overlap between theirmotion.

In a preferred embodiment of the invention, said two spikes are extendedby a same distortion of said cylinder-like portion. Alternatively, theextension of at least one of said spikes is decoupled from distortion ofsaid cylinder-like portion.

In a preferred embodiment of the invention, said two spikes are extendedby different degrees of radial expansion of said cylinder-like portion.

In a preferred embodiment of the invention, said extension comprisesimpaling a portion of a blood vessel. Alternatively or additionally,said extension comprises transfixing a portion of a blood vessel.Alternatively or additionally, said extension comprises pinching aportion of a blood vessel.

There is also provided in accordance with a preferred embodiment of theinvention, an anastomotic connector for attaching two blood vessels,comprising:

-   -   a cylinder-like portion defining a lumen; and    -   a plurality of tissue engaging portions for engaging the two        blood vessels,    -   where said connector has at least two configurations, a first        configuration in which said tissue engaging portions are at a        first extension state and a second configuration where said        tissue engaging portions are at a second extension state, where        said connector exhibits a bi-modal behavior in changing from        said first configuration to said second configuration.

Preferably, said configuration change is effected by expanding saidcylinder-like portion. Alternatively or additionally, said configurationchange comprises the extension of a plurality spikes. Alternatively oradditionally, the connector comprises at least one bi-stable elementthat controls said configuration change. Alternatively or additionally,the connector comprises at least one restraining element that controlssaid configuration change.

There is also provided in accordance with a preferred embodiment of theinvention, an anastomotic connector for attaching two blood vessel,comprising:

-   -   a cylinder-like portion defining a lumen; and    -   a plurality of tissue engaging portions for engaging the two        blood vessels,    -   where said connector has at least two configurations, a first        configuration in which said tissue engaging portions form a        vessel piercing tip and a second configuration where said tissue        engaging portions are operative to engage tissue.

Preferably, said plurality of tissue engaging portions comprise at leastone spike. Alternatively or additionally, said plurality of tissueengaging portions are arranged at one end of said cylinder-like portionsand the connector comprises a second plurality of tissue engagingportions adjacent the other end of said cylinder-like portion.

There is also provided in accordance with a preferred embodiment of theinvention, an implantable device comprising:

-   -   a first portion designed to come in contact with blood; and    -   a second portion designed not to come in contact with blood,    -   where said second portion is coated with a coagulation-promoting        material.

Preferably, said device is an anastomosis connector. Alternatively oradditionally, said device is a vascular device for sealing a hole in ablood vessel.

In a preferred embodiment of the invention, said first portion is coatedwith a coagulation-retarding material.

There is also provided in accordance with a preferred embodiment of theinvention, a graft kit, comprising:

-   -   a sterility-maintaining packaging; and    -   a graft having at least two ends and having a side-to-end        anastomotic connector attached to at least one of said two ends,        where said anastomotic connector includes spikes for engaging a        blood vessel.

Preferably, the kit comprises a restrainer for maintaining said spikesin an unengaged configuration.

There is also provided in accordance with a preferred embodiment of theinvention, a graft comprising:

-   -   a tubular body having at least one intersection, such that said        body has at least three ends; and    -   at least two end-to-side anastomotic connectors attached to at        least two of said three ends.

There is also provided in accordance with a preferred embodiment of theinvention, a hole puncher, adapted for punching a hole in a bloodvessel, comprising:

-   -   an outer tube having distal portion, which distal portion has a        lip;    -   a punch element having a sharp tip and defining a depression        distal from the tip, where said depression is of a size adapted        to receive a blood vessel,    -   where said distal portion of said outer tube has an outer        diameter which is substantially the same as an outer diameter of        said punch element and where said punch element fits snugly in        said distal portion such that said lip can sever blood vessel        tissue contained in said depression from tissue outside said        depression.

Preferably, said depression is distanced from said tip so that saiddistance is at least the thickness of the blood vessel. Alternatively oradditionally, said puncher is flexible enough to be provided through ablood vessel in which a hole is to be punched.

In a preferred embodiment of the invention, the puncher comprises ahandle. preferably, the puncher comprises means for advancing said outertube relative to said handle and relative to said punch element.Alternatively or additionally, the puncher comprises means forretracting said punch element relative to said handle and relative tosaid outer tube.

In a preferred embodiment of the invention, the puncher comprises meansfor advancing a graft into said hole formed by said punch. Alternativelyor additionally, the puncher comprises a valve for preventing blood fromleaking out of said outer tube once said punch element is removed.Alternatively or additionally, said distal end comprises a stop forpreventing entry of said distal end into said hole beyond said stop.Preferably, said stop is at an oblique angle relative to a main axis ofsaid distal end, to guide said hole puncher to form an oblique punch.

In a preferred embodiment of the invention, the puncher comprises a stopfor prevention advance of said punch element relative to said distalend, beyond a pre-defined distance. Alternatively or additionally, saidpunch element is radially expandable from a first, small diameter to asecond, working diameter. Alternatively or additionally, said distal endis radially expandable from a first, small diameter to a second, workingdiameter. Alternatively or additionally, said depression in said punchelement is at an oblique angle relative to a main axis of said punchelement, whereby an oblique hole is punched thereby. Alternatively oradditionally, said lip of said outer tube is at an oblique anglerelative to a main axis of said outer tube, whereby an oblique hole ispunched thereby. Alternatively or additionally, said hole puncher isarranged to punch an oblong hole.

There is also provided in accordance with a preferred embodiment of theinvention, apparatus for everting a vessel over an anastomoticconnector, comprising:

-   -   a vessel holder for holding said vessel; and    -   an expander, adapted to engage said vessel, at least at an end        of said expander, which expander expands from a diameter of less        than a diameter of said vessel to a diameter greater than that        of said vessel and where in said expanded diameter, said at        least said portion can enclose at least a portion of said vessel        holder.

Preferably, the apparatus comprises means for selectively moving saidexpander relative to said vessel, such that said engaged portionoverlaps said vessel holder. Alternatively or additionally, theapparatus comprises a holder for an anastomotic connector. Preferably,the apparatus comprises a retainer for maintaining said anastomoticconnector in a desired configuration during at least a portion of saideversion.

In a preferred embodiment of the invention, apparatus is separable intotwo pieces. Alternatively or additionally, the apparatus comprises aguide for maintaining coaxiallity between said vessel holder and saidexpander. Preferably, said guide comprises an intra-lumen vessel engagerfor engaging said vessel.

There is also provided in accordance with a preferred embodiment of theinvention, a tip mechanism for forming a hole in a blood vessel, frominside the blood vessel, comprising:

-   -   a wire portion;    -   a tip coupled to said wire portion; and    -   a motor coupled to said tip and adjacent to said tip.        Preferably, said wire is at least 10 cm long.

In a preferred embodiment of the invention, said tip is a sharp tip.Alternatively or additionally, said motor is a piezoelectric motor.Alternatively, said motor is a magneto-strictive motor. Alternatively,said motor moves said tip in a rotational motion around a main axis ofsaid wire.

In a preferred embodiment of the invention, said motor moves said tip inan axial motion along a main axis of said wire.

In a preferred embodiment of the invention, said tip is smooth.Alternatively, said tip includes protrusions for engaging soft tissue.

In a preferred embodiment of the invention, said tip has a geometrymatched to a geometry of said motor, such that an amplitude of motion ofsaid tip is at least twice the amplitude of said motor.

There is also provided in accordance with a preferred embodiment of theinvention, a patch for sealing a hole in a blood vessel, comprising:

-   -   a body which can be selectively collapsed or expanded, such that        the patch fits inside an catheter having a diameter suitable for        travel in said blood vessel;    -   a plurality of tissue engaging elements on said patch; and    -   a seal,    -   where, when said device is expanded, placed over the hole and        the tissue engaging elements engage said vessel, said seal seals        said hole.

There is also provided in accordance with a preferred embodiment of theinvention, a framework for an endoscopic procedure, comprising:

-   -   a body which can be selectively collapsed or expanded, such that        it fits through a tube used to access a surgical area;    -   fixation members for attaching said body to tissue at said        surgical area; and    -   guidance members for guiding one or more tools at said area to        perform said endoscopic procedure,    -   where said body is operative not to be rigidly coupled to said        tube while in a surgical area.

Preferably, said framework has a plurality of stable configurations andwhere said stable configurations are matched to a particular endoscopicprocedure. Preferably, said configurations are achieved by selectivelyinflating at least one balloon coupled to said framework.

In a preferred embodiment of the invention, the framework comprises asafety line for attaching said framework to a tool which exits saidbody. Alternatively, is unattached to said tube.

There is also provided in accordance with a preferred embodiment of theinvention, a method of performing a bypass, comprising:

-   -   transvascularly providing a graft at a first location in a        vascular system;    -   forming a hole at said location;    -   expelling at least most of said graft out of said hole;    -   navigating said graft adjacent a second hole in said vascular        system;    -   forming a hole at said second location;    -   percutaneously performing a first independently patent        anastomosis at said first location, which anastomosis does not        occlude said vascular system at said first location; and    -   percutaneously performing a second independently patent        anastomosis at said second location, which anastomosis does not        occlude said vascular system at said second location.        Preferably, at least one of said first and said second        anastomotic connections is performed such that no portion of an        anastomotic connector remains in contact with blood in said        vascular system. Alternatively or additionally, at least one of        said first and said second anastomotic connections is a        side-to-side anastomosis. Alternatively or additionally, at        least one of said first and said second anastomotic connections        is a side-to-end anastomosis. Alternatively or additionally, at        least one of said first and said second anastomotic connections        is an intima-to-intima anastomosis. Alternatively or        additionally, at least one of said first and said second        anastomotic connections is an anastomosis between an intima and        a inside of a vessel wall.

In a preferred embodiment of the invention, at least most of a graftcomprises all of the graft. Alternatively, at least most of a graftcomprises all of the graft except for a lip thereof.

In a preferred embodiment of the invention, only an intima of said lipis exposed to blood in said vascular system.

In a preferred embodiment of the invention, expelling at least most of agraft comprises expelling all of the graft out of the lumen of saidvessel while maintaining a portion of said graft in a cross-section ofsad vessel wall.

There is also provided in accordance with a preferred embodiment of theinvention, a method of performing an anastomosis, comprising:

-   -   transvascularly providing a graft at a location in a vascular        system;    -   forming a hole at said location;    -   expelling said graft completely out of said hole; and    -   transvascularly performing an independently patent anastomosis        at said location, which anastomosis does not occlude said        vascular system at said location. Preferably, said anastomosis        is a side-to-end anastomosis. Alternatively, said anastomosis is        an end-to-end anastomosis.

In a preferred embodiment of the invention, said anastomosis isperformed using an anastomotic connector and where said connector iscompletely outside a blood flow of said vascular system after saidanastomosis.

Alternatively or additionally, said anastomosis is performed using ananastomotic connector and where said only spike portions of saidconnector are in contact with a blood flow of said vascular system aftersaid anastomosis.

Alternatively or additionally, said anastomosis is performed using ananastomotic connector and where said connector forms said hole.

There is also provided in accordance with a preferred embodiment of theinvention, a method of anastomosis comprising:

-   -   providing an expandable anastomotic device; and    -   inflating said device to simultaneously open an anastomotic        passage and perform an anastomotic connection.

There is also provided in accordance with a preferred embodiment of theinvention, a method of anastomosis attachment comprising:

-   -   inserting an anastomotic device to attach two blood vessels; and    -   inflating a balloon in said device if said attachment leaks.

There is also provided in accordance with a preferred embodiment of theinvention, a method of punching a hole in a blood vessel, comprising:

-   -   providing a hole puncher to a location in a vascular system,        which location has blood flowing therethrough;    -   transfixing a wall of said vascular system at said location;    -   removing a portion of said wall using said hole puncher, while        said hole-puncher remains transfixing said wall; and    -   transporting a tool across said wall through a lumen of said        hole puncher.

Preferably, said removing comprises partially retracting a portion ofsaid hole puncher.

Alternatively or additionally, said removing comprises partiallyadvancing a portion of said hole puncher.

In a preferred embodiment of the invention, the method comprises usingsaid tool to perform an anastomosis connection. Alternatively oradditionally, said providing is from inside of said vascular system.Alternatively or additionally, said providing is from outside of saidvascular system.

There is also provided in accordance with a preferred embodiment of theinvention, a method of everting a graft over an anastomotic connector,comprising:

-   -   sliding said anastomotic connector over said vessel, to a point        adjacent an end of the vessel;    -   expanding a portion of said vessel between said point and said        end; and    -   everting said expanded portion over of said connector.        Preferably, said everting and said expanding use a same tool.

In a preferred embodiment of the invention, the method comprisestransfixing said vessel at or about said portion with an anastomoticconnector.

There is also provided in accordance with a preferred embodiment of theinvention, a method of performing a side to end anastomosis, comprising:

-   -   providing a graft to a location on a side of a blood vessel;    -   forming a hole in said side blood vessel;    -   engaging one face of said side of the blood vessel, using an        anastomosis connector to perform a first portion of the        anastomosis; and    -   completing the anastomosis by engaging the second face of said        side using the anastomosis connector.

Preferably, said providing is from inside of said blood vessel.Alternatively, said providing is from outside of said blood vessel.

There is also provided in accordance with a preferred embodiment of theinvention, a method of performing a bypass procedure, comprising:

-   -   transvascularly providing a graft at a first location in a        vascular system;    -   expelling at least most of said graft out of a hole at said        first location;    -   navigating an end of said graft to a second location in said        vascular system;    -   performing an anastomosis at said second location; and    -   thereafter transfixing said graft to said vascular system at        said first location, using an anastomotic connector.

There is also provided in accordance with a preferred embodiment of theinvention, a method of performing an anastomosis, comprising:

-   -   providing a graft at a location in a vascular system;    -   forming a hole at said location; and    -   simultaneously expanding said hole and completing an anastomotic        connection between said graft and said vascular system at said        location. Preferably, said forming and said expanding comprises        a continuous process. Alternatively, said forming and said        expanding comprises a discrete step process.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood by reference to thefollowing description of preferred embodiments thereof in conjunctionwith the figures, wherein identical structures, elements or parts whichappear in more than one figure are labeled with the same numeral in allthe figures in which they appear, in which:

FIG. 1 illustrates a heart with at least one clogged artery and showinga desirable bypass path;

FIGS. 2A–2I illustrate a bypass technique in accordance with a preferredembodiment of the invention;

FIGS. 2J–2P illustrate a variation of the method of FIGS. 2A–2I, inaccordance with a preferred embodiment of the invention;

FIGS. 2Q–2T illustrate hole making mechanisms in accordance withpreferred embodiments of the invention;

FIGS. 2TA and 2TB illustrate a method of punching a hole in a bloodvessel, in accordance with a preferred embodiment of the invention;

FIGS. 2U–2W illustrate end-to-end anastomosis connections in accordancewith preferred embodiments of the invention;

FIGS. 3A–3H, 3HA and 3I–3O illustrate different types of side-to-end andend-to-end joints, achievable in accordance with preferred embodimentsof the invention;

FIG. 3P illustrates a side-to-side anastomosis, in accordance with apreferred embodiment of the invention;

FIGS. 4A–4D illustrate a one piece anastomosis connector, in a plan viewand in various stages of deployment, in accordance with preferredembodiments of the invention;

FIG. 4E illustrates a one piece anastomosis connector, in accordancewith another preferred embodiment of the invention;

FIGS. 4F–4I illustrate anastomosis connectors which require a minimumamount of user intervention, in accordance with a preferred embodimentof the invention;

FIG. 4J illustrates an oblique anastomotic connector in top, isometricand side views thereof;

FIG. 4K illustrates the connector of FIG. 4J, as deployed in a completedoblique anastomosis;

FIG. 5 is a graph illustrating various possible couplings between radialexpansion and axial contraction in an anastomosis connector as shown inFIG. 4A;

FIGS. 6A–6E illustrate an additional one piece anastomosis connector andits deployment, in accordance with a preferred embodiment of theinvention;

FIGS. 7A and 7B illustrate a pin based anastomosis device, in accordancewith a preferred embodiment of the invention;

FIGS. 7C–7N illustrate various mechanisms for extending spikes out of asurface of the anastomotic device, in accordance with a preferredembodiment of the invention;

FIG. 7O illustrates a parallelogram portion of a connector, whichincludes a ratchet mechanism for preventing collapsing of the connector,in accordance with a preferred embodiment of the invention;

FIGS. 7P–7R illustrate a two stage folding of a pair of spikes, inaccordance with a preferred embodiment of the invention;

FIGS. 7S–7T illustrate a connector with cantilevered spikes, inaccordance with a preferred embodiment of the invention;

FIGS. 7U–7V illustrate a bi-stable spike configuration, in accordancewith a preferred embodiment of the invention;

FIGS. 8A–8E illustrate an implantation of an orientation independent twopiece anastomosis device and an exemplary device, in accordance with apreferred embodiment of the invention;

FIGS. 8F–8I illustrate various configurations of anastomoticconnections, in accordance with preferred embodiments of the invention;

FIGS. 8J–8M and 8O–8P illustrate a family of alternative anastomoticconnectors and their deployment, in accordance with preferredembodiments of the invention;

Figure designation 8N has been intentionally skipped;

FIGS. 8Q–8R illustrate a pull-wire anastomotic device, in accordancewith a preferred embodiment of the invention;

FIGS. 8S–8X illustrate alternative mechanisms for folding spikes inwhich a radial expansion is substantially decoupled from axial lengthchanges, in accordance with preferred embodiments of the invention;

FIGS. 8XA–8XH illustrate a family of mechanisms for axial retractionand/or extension of spikes, in accordance with preferred embodiments ofthe invention;

FIGS. 9A–D illustrate additional devices for attaching graft material toblood vessels, in accordance with preferred embodiments of theinvention;

FIGS. 10A–10D illustrate an end-to end anastomosis in accordance with apreferred embodiment of the invention;

FIGS. 10E–10K illustrate an end-to-end anastomosis in accordance with analternative preferred embodiment of the invention;

FIG. 10L illustrates a side-to-side anastomosis, utilizing a connectorsimilar to that used in the embodiments of FIGS. 10E–10K;

FIG. 10M shows a front view of an anastomosis device suitable for use inFIGS. 10E–10L;

FIG. 11 illustrates a transvascular graft delivery system, in accordancewith a preferred embodiment of the invention;

FIGS. 12A–E illustrates a key-hole based graft delivery system, inaccordance with a preferred embodiment of the invention;

FIGS. 12F and 12G illustrate anastomotic connectors suitable for theembodiment of FIGS. 12A–E;

FIGS. 12H–12J illustrate a graft everter, in accordance with a preferredembodiment of the invention;

FIGS. 12K–12M illustrate an alternative hole-punching sub-assembly, inaccordance with a preferred embodiment of the invention;

FIGS. 12N–12R illustrate two methods of punching a preferably leak-lesshole from outside or inside a blood vessel, in accordance with apreferred embodiment of the invention;

FIGS. 12S and 12T illustrate an expanding hole puncher, in accordancewith a preferred embodiment of the invention;

FIGS. 13A–D illustrate a method of separately providing an anastomoticconnector and a graft, at an anastomosis site, in accordance with apreferred embodiment of the invention; and

FIGS. 14A–D illustrate a method of cutting a graft to size, during ananastomosis process in accordance with a preferred embodiment of theinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 illustrates a heart 20 having an artery 22 that is clogged, forexample, at an occlusion location 24. One medical solution is to providea graft 26 that connects between an aorta 30 and a point 28 downstreamfrom occlusion 24. Graft 26 is usually connected to aorta using aside-to-end anastomosis 32. The anastomosis at point 28 is usually alsoa side-to-end anastomosis.

FIGS. 2A–2I illustrate a bypass technique in accordance with a preferredembodiment of the invention, in which most or all of a cardiac bypassprocedure may be performed percutaneously, without opening the chest. Ina preferred embodiment of the invention, the entire technique can bepracticed transvascularly. In a preferred embodiment of the invention, aCABG (Coronary Artery Bypass Graft) procedure is performed. Similartechniques are described in Israel patent application serial number124,694, filed May 29, 1998, with a like title, the disclosure of whichis incorporated herein by reference.

Preferably, the initial step is to harvest a graft from the body of thepatient or otherwise provide it. Thereafter, one or more anastomosisconnectors are preferably attached to the graft. Alternatively oradditionally, the graft comes with ready made anastomosis connectorsattached thereto (possibly provided in a kit form or by a technician).The anastomosis connectors are preferably selected to match the bloodvessel diameters, conditions and/or other parameters of the anastomosis.In some embodiments of the invention, the anastomosis device is providedseparately from the graft to an anastomosis location and the device andthe graft are connected near or at the anastomosis connection (see FIG.13, below).

FIG. 2A illustrates a first step, in which a catheter 34, preferably aJ-shaped catheter, is brought into contact with the wall of aorta 30,with the end of the catheter generally directed towards coronary artery22. The catheter is preferably inserted into the body through thearterial system, for example via the femoral artery.

In a preferred embodiment of the invention, the J-shaped catheter is abendable catheter that is bent so that the bend area (not shown) restsagainst the aorta opposite the tip of the catheter, thus, providing aforce that maintains the catheter tip in its position. In some preferredembodiments of the invention, the catheter is a bendable catheter, forexample by inserting a suitable stylet. Alternatively, the catheter tipmay include suction, clamping and/or other mechanism, which attach thecatheter tip directly to the aorta wall (described below).

In FIG. 2B, a thin guide-wire 36, having a sharp tip 37 is pushed outthrough the wall of aorta 30, creating a hole 35. Preferably, catheter34 is pressed against the wall of aorta 30, so no blood escapes.Alternatively or additionally, and especially if the diameter of wire 36is small, the elasticity of aorta 30 closes onto the wire and maintainsleakage integrity. Although the Fig. shows a barbed guide wire, theguide wire tip may also comprises a smooth taper.

Alternatively, the guide wire tip may be used to punch out a portion ofthe aorta, when the guide wire is pulled back into the aorta.

In some preferred embodiments of the invention, a protective sleeve (notshown) interposes between the guiding catheter and the guide wire.Possibly, this protective sleeve is used to bend the catheter and/or tomaintain the guide wire in a J-shaped configuration.

In a preferred embodiment of the invention, the guiding catheter is anendoscope comprising a plurality of working channels, for example, onefor the graft and others for other tools, for example a saline washingfluid provider.

In FIG. 2C a graft 38 is pushed out of hole 35 and into the chestcavity. Preferably, graft 38 is preloaded with at least one anastomosisconnector, for example an aortic anastomosis connector 42 and/or acoronary anastomosis connector 40. Alternatively, one or both theconnectors may be attached to the graft after it is inserted into thebody. It should be noted that in some preferred embodiments of theinvention, not all of aortic anastomosis connector 42 exits the aorta.In a preferred embodiment of the invention, the size and/or shape ofconnector 42 is selected so that the graft is properly aligned withrespect to the thickness of the aortic wall. In one example, theconnector has an hourglass shape, in which the waist engages the aorticwall. In another example, connector 42 includes lips, which preventconnector 42 from exiting the aorta. Possibly, connector 42 includes asecond pair of lips (not shown) which engage the outside of the aorta.

In FIG. 2D, graft 38 is attached to aorta 30, preferably usinganastomosis connector 42. Alternatively or additionally, the graft isattached by gluing, welding or suturing. Alternatively or additionally,the graft is sewn, for example using a loaded needle device, such asshown in PCT publication WO 98/42262. Preferably, the device is madesmaller and flexible, so as to be suitable for transvascular use,especially for providing the device through the graft to engage acoronary vessel and to attach the graft thereto. In a preferredembodiment of the invention, stapling is performed via a keyhole openedin the chest. Alternatively or additionally, welding is achieved bypassing an electric current through the anastomosis connector itself toheat the connector or to provide current through the vessel wall.Alternatively or additionally, the anastomosis is performed by expandinga balloon or another types of expandable device inside anastomosisconnector 42 and the expansion causing the connector to perform theanastomosis. Alternatively or additionally, connector 42 is superelastic, elastic or shape-memory and once a restraint is removed,distorts into a configuration suitable for anastomosis. Alternatively oradditionally, one or more balloons and/or expandable frameworks areurged against each other with connector 42 held between them, so thatconnector 42 creates the anastomosis.

It should be noted that, in accordance with some preferred embodimentsof the invention, the graft-aorta anastomosis is patent on its own.Preferably, graft 38 is blocked, for example using a balloon along guidewire 36 so that blood does not leak out its distal end.

In FIG. 2E, graft 38 and/or guide-wire 36 are navigated so that tip 37of the guide wire is near coronary artery 22. Such navigation preferablyincludes two elements, first, actually guiding the guide wire andsecond, directing the guide wire to a correct location. In some cases,for example if the guide wire is rigid, the navigation step might beperformed before the aortic anastomosis step, possibly with some of thegraft still inside the aorta. The navigation itself may serve to pullthe graft out of the aorta. Typically however, most or all of graft 38is passed out of the aorta prior to performing the navigation.

The guide-wire may be guided using many methods known in the art,including controllable guide wires and outer sleeves of differentshapes. Direction of the guide wire may use a real-time image of theguide wire and/or the surrounding tissue or it may use a pre-determinedrepresentation of the body. In a preferred embodiment of the invention,a real-time catheter location system is used to determine the relativelocations of tip 37 and point 28 on coronary 22. One such locationsystem is available from Johnson & Johnson Biosense Ltd., of TiratHacarmel, Israel. Alternatively or additionally, the navigation isperformed using a real-time or near real-time image provided by animaging system, such as ultrasound, CT, fluoroscopy and MRI. In somenavigation systems it may be necessary to mark point 28 (FIG. 1) oncoronary 22. Such marking may be achieved by using a contrast material,a radio-opaque marker, a magnetic marker or an intra-body beacon. Insome cases, it may be desirable to insert a catheter into artery 22,with such a marker at its tip, to facilitate navigation of catheter tip37.

If graft 38 is already attached to aorta 30, the graft is preferablyuncovered while it snakes around the inside of the body. Alternativelyor additionally, an outer sleeve may cover the graft and protect it fromcontact with internal body tissues. If the aortic anastomosis is alreadyperformed, such a covering is preferably flexible and is preferablyremoved by pulling back it through the “coronary” end of the graft.

An ultrasound imager, especially at or near tip 37 may also be used todetermine which obstacles lie ahead of tip 37 and/or to help guideand/or position it. Alternatively or additionally, methods as describedin the “Transvascular applications”, in the background, may be used. Ina preferred embodiment of the invention, graft 38 is attached to bodytissue, for example membranes, muscle, and/or blood vessels, along itslength. Such attaching may be performed after the anastomosis isfinished. Alternatively or additionally, such attaching is performedduring the navigation step. The attaching may be achieved by pushingclips out of the lumen of graft 38 and into the tissue. Alternatively oradditionally, graft 38 may be preloaded with such clips, which aremaintained in a “open” position using a restraint. When the restraint isremoved, the clips close and attach to a nearby tissue. Alternatively oradditionally, the graft is attached along its length using tissue glue,welding, suturing or other techniques of tissue attachment.

In some preferred embodiments of the invention, the graft may benavigated into the pericardium and along the heart. Alternatively, thegraft may enter the pericardium only at a point near the point 28 onvessel 22. Alternatively or additionally, the graft may travel and/ormay remain inside the lumen of an organ, such as the lungs or even ablood vessel, such as a vena cava.

Once tip 37 is near coronary vessel 22, the far anastomosis may be made.Preferably, tip 37 is inserted into vessel 22, as shown for example inFIG. 2F, so that graft 38 can be connected to vessel 22. In a preferredembodiment of the invention, a suction, clamping, grasping or anothertype of attaching device is coupled to guide wire 36 and/or graft 38.This attaching device is used to steady the graft end and/or the guidewire relative to moving tissue, such as a beating heart. The attachmentdevice may attach forward of the advancing wire or to its side. In someembodiments, the guide wire may pass through the attachment deviceand/or the graft may pass over the attachment device. Possibly, theattachment device is used to remove a portion of the coronary vessel,once the guide wire is properly positioned. In a preferred embodiment ofthe invention, graft 38 and/or guide wire 36 are enclosed by (orenclose) an endoscope, or are provided side-by-side. An attachmentdevice may be provided through one of the working channels of theendoscope or from inside the graft.

In a preferred embodiment of the invention, prior to insertion of tip 37into the blood vessel, the entry area is cleaned and a thin coatinglayer of tissue is removed. In some cases, the tissue layer may compriseheart muscle which overlies the coronary. In other cases, the layer maycomprise a coating membrane, for example an adventitia layer. In apreferred embodiment of the invention, this tissue is removed using aknife-like excavating tool which is provided through one of the aboveworking channels or by transverse motion of tip 37 itself.

In a preferred embodiment of the invention, connector 40, in its closedconfiguration, serves the functions described above for tip 37. In apreferred embodiment of the invention, tip 37 comprises a screw, whichis screwed into vessel 22, to create a hole 39 in vessel 22.Alternatively or additionally, a stabilizing tool is guided overguidewire 36, to stabilize vessel 22 relative to tip 37. In a preferredembodiment of the invention, the stabilizing tool is a suction devicewhich attaches itself to vessel 22 or to tissue in a vicinity thereof.Preferably, tip 37 is guided through the suction device. Alternativelyor additionally, the stabilizing tool includes a tip having across-section shape which matches the cross-section of coronary 22, at adesired approach angle. Alternatively or additionally, the stabilizingdevice comprises jaws which grab vessel 22. Preferably, the jaws pinchvessel 22, so that a desired entry point for tip 37 is adjacent tip 37.Preferably, vessel 22, in its pinched configuration, presents a narrowaspect to tip 37 and a wide aspect perpendicular thereto, so there isless danger of perforating both sides of vessel 22. Alternatively oradditionally, the wide aspect is presented to tip 37, to make aimingeasier. Such aiming preferably uses an imager and/or a Doppler sensor(preferably depth gated) to detect the location of flow in vessel 22.

In FIG. 2G, graft 38 is advanced to hole 39 and/or a portion ofanastomosis connector 40 is inserted into hole 39. A balloon ispreferably guided along guide wire 36 and inflated inside connector 40,so that it expands the anastomosis connection and creates an attachmentbetween vessel 22 and graft 38. Preferably, the balloon is tapered sothat it more easily inserted into connector 40. Alternatively oradditionally, connector 40 elastically increases in diameter, once it isplaced into hole 39 and a restraint removed, to allow enough space forthe balloon. Alternatively or additionally, two balloons are used, anarrow one which partially inflates the connector and a wider balloonwhich completes the inflation of the connector. The leading end of graft38/connector 40 are preferably tapered, so that they are more easilyguided into vessel 22. Alternatively or additionally, guide wire 36 isinserted into vessel 22 for a considerable distance and/or bent, so thatthere is less chance of guidewire 36 inadvertently leaving vessel 22.

The result, as shown in FIG. 2H is that graft 38 bridges aorta 30 andvessel 22. Typically, the holes in the blood vessels and the anastomosissites are stabilized and patent even without the continued assistance ofthe connector, within two weeks. Thus, in some cases, the anastomosisconnector may be formed of a bio-degradable substance. In some preferredembodiments of the invention, tissue glue or other blood-blockingmaterials are applied to one or both of the anastomosis sites, possiblywhere the two blood vessels contact each other or the anastomoticdevice. In one example, these substances are applied using keyholesurgery. In another example these substances are applied using a needlewhich exits through the side of the graft or one of the blood vessels.

In a preferred embodiment of the invention, coagulating materials areapplied outside the blood vessels or at the contact area of the bloodvessels. Alternatively or additionally, anti-coagulation materials areapplied to portions of the anastomosis and/or anastomosis connectorwhich are inside the blood flow. In a preferred embodiment of theinvention, the coagulation control materials and/or the tissue gluingmaterials are applied by coating them onto the anastomotic connector, atcertain portions thereof. Alternatively or additionally, coagulationand/or tissue re-growth may be affected by making some of theanastomotic device or a catheter brought to the anastomosis area,radioactive.

In a preferred embodiment of the invention, an anastomotic connectorincludes a telemetried pressure sensor or a blood velocity meter, sothat the patentcy of the connector can be assessed after the connectoris implanted. Alternatively or additionally, the connector includes oneor more radio-opaque wires or markers so that it is easy to determine(using x-rays) if the connector is maintaining a proper configuration.In a preferred embodiment of the invention, leakage of the device isdetermined by injecting a radioactive bolus of a chemical not absorbedby the body after the connection is completed. After the bolus isdiluted in the blood or removed from the body, checking if the area ofthe anastomosis exhibits radioactivity, which radioactivity would beindicative of leakage and/or clotting at the connector. Preferably ashort-decay radioactive material is used, to minimize radioactiveexposure of the patient.

FIGS. 2J–2P describe a variation on the method described above withreference to FIGS. 2B and 2C. Not all the required elements are shown inall the figures, for reasons of clarity and for reducing visual clutter.In a preferred embodiment of the invention, connector 42 is not directlypushed into a hole formed in the aorta by the guide wire. Rather, thehole is first expanded using a balloon or another expandable device andthen the connector is inserted into the expanded hole. Alternatively, aguiding sheath is inserted into the hole and the connector is insertedthrough the sheath. Then, the sheath is removed, leaving the connectorin the hole. In some embodiments, the sheath is a working channel of anendoscope. other working channels of the endoscope may be used for toolswhich assist in one or both of the anastomosis connections and/or withthe navigation.

In FIG. 2J, a balloon 300 is advanced over guide wire 36 into the holemade by the guide wire and then inflated. Possibly, balloon 300 isattached to the guide wire and is advanced into the hole by advancingguide wire 36. Balloon 300 is preferably inflated so that it expands thehole made by guide wire 36 (as explain herein by poking a hole or byremoving a portion of the vessel wall), until it is wide enough for aguiding catheter 302 to enter the hole.

In FIG. 2K, Balloon 300 is advanced so that it pulls guiding catheter302 into the expanded hole. Alternatively, catheter 302 is pushed overthe balloon. In a preferred embodiment of the invention, catheter 302has a rigid cross-section, to which size the balloon is expanded.Alternatively, the catheter has a flexible and/or elastic cross-section,which conforms to the shape of the balloon.

In a preferred embodiment of the invention and as indicated in FIG. 2J,part of balloon 300 is inside the catheter and part is out side. In apreferred embodiment of the invention, both parts of the balloon expandto a same radius. Alternatively, the part outside the balloon may expandmore, so that guiding catheter 302 more easily slips into the expandedhole. Alternatively or additionally, the outside of catheter 302 may becoated with a material having a low coefficient of friction (withrespect to the blood vessel), to assist in the catheter entering thehole. Alternatively or additionally, the end of catheter 302 may extrudea lubricant. Alternatively or additionally, the outside of catheter 302may include mechanical means to assist insertion, for example, theoutside of catheter 302 may be threaded, so that the catheter can bescrewed into the hole.

FIG. 2L shows a catheter 302 in position in the hole. Generally, theseal between the aorta wall and the catheter is tight enough so thatthere is little or no leakage of blood from the hole. Thus it ispossible to bring various tools through the catheter to performactivities outside the blood vessel, for example at the coronaryanastomosis. As a result, the far anastomosis may be performed and/orcorrected, if necessary, prior to performing the near anastomosis.Possibly, the inner radius of catheter 302 is greater than the finalinner radius of the graft, to facilitate such remote activities.Possibly, the radius of catheter 302 increases after the it exits hole35. The above tools may be brought through the graft (once it isinserted into the aorta. Alternatively, the tools may be brought throughthe catheter at the side of the graft. Possibly, the graft itself isonly brought in after some activities are performed at the remoteanastomosis, for example locating and/or fixing a guidewire to theanastomosis location. Alternatively, the graft may be passed completelythrough the hole in the aorta and then one end of the graft possiblybrought back to attach to the hole. Alternatively, the one end isattached to a vessel other than the aorta or to the aorta at a positionother than the hole. Preferably, the hole is closed using other means,such as a patch, or by attaching a second graft from the hole to anotherremote anastomosis location.

In FIG. 2M, graft 38 is positioned so that an anastomotic connector 42is in hole 35. In a preferred embodiment of the invention, as shown forexample in FIG. 2C for connector 40, connector 42 comprises lips whichprevent the connector from advancing beyond hole 35. Alternatively oradditionally, connector 42 has an hourglass profile so it self-centersin hole 35. In a preferred embodiment of the invention, catheter 302 hasa flexible exterior, so that connector 42 can engage hole 35 through theintervening catheter. Alternatively, catheter 302 has an inflexibleexterior geometry which, itself, engages the hole. Preferably, catheter302 also has a suitable interior geometry, so that when graft 38 andconnector 42 are inserted, they are properly aligned with hole 35. InFIG. 2M, an endoscope 306 is shown, in accordance with preferredembodiments of the invention. This endoscope may be used to provideballoons, grafts, connectors and/or for navigation of the graft to theremote anastomosis location.

Thereafter, guiding catheter 302 may be retracted, for example as shownin FIG. 2N, to allow connector 42 to engage hole 35 in aorta 30.Generally, hole 35 will shrink and engage connector 42 so that there isno leakage. Alternatively, catheter 302 may remain abutting against thewall of aorta 30, to prevent bleeding. Preferably, the far end of graft38 is sealed to prevent blood from leaking out through the graft (unlessthe far end is already attached to a blood vessel).

In FIG. 2O, a balloon 304 is expanded inside connector 42. Possibly,balloon 304 is provided into the connector prior to the removal ofcatheter 302. Alternatively, it is provided, after the removal,preferably being guided over guide wire 36. Alternatively to using aballoon, connector 42 may comprise a super-elastic, elastic and/orshape-memory material which expands when an constraint (e.g., catheter302 or guide wire 36) is removed.

In a preferred embodiment of the invention, the expanded geometry ofballoon 304 is matched to the desired shape of the expanded anastomosisdevice. In one example, Balloon 304 comprises fingers which extend tobend spike-portions of the connector (described below). In anotherexample, Balloon 304 expands to an hour-glass shape, to better positionand/or shape connector 42. Alternatively or additionally, balloon 304axially shortens when it radially expands, to assist in the correctshaping of connector 42. Alternatively or additionally, balloon 304comprises a multi-step balloon which expands in a step-wise manner tosequentially provide a plurality of different geometry's. The selectionbetween the geometry's may depend on the inflation pressure, for exampleby providing thicker and thinner portions in the balloon, where thethicker ones require a greater pressure to stretch, or on a positionand/or rotation of a guide wire which is enclosed by the balloon. In oneexample, A first inflation pressure causes the balloon to expand to afirst step, where spikes on the connector are extended perpendicular tothe surface of the connector. A second inflation pressure causes thespikes to bend another 90 degrees and a third inflation pressure causesthe connector to expand and/or axially shrink.

In FIG. 2P, the aortic anastomosis is complete and the coronaryanastomosis is ready to be performed (if not already performed).

It should be noted that although a plurality (possibly even four) ofballoons may be used for expansion of the various hole sand anastomoticconnectors, possibly a smaller number of balloons or even a singleballoon may suffice. In one example, a single balloon comprises amulti-step balloon whose final geometry is step-wise dependent on theinflation pressure. In an extreme example, no balloon is used, forexample, if the connectors are self-expanding and/or by using anon-balloon expandable structure. One example of a non-balloonexpandable structure comprises of two base-to base tetrahedrons, inwhich the non-base sides are rigid and in which the two opposingvertexes are attached by a wire which may be shortened (e.g., by pullingthe wire).

Alternatively or additionally to end-to-side anastomosis connections atthe coronary end illustrated in FIG. 2H, side-to-side anastomosisconnections may be used, as described for example in the “Transvascularapplications”. FIG. 2I shows an example of such connections, where asingle graft 38 is attached to two, possibly different coronary arteries22. The end of graft 38 is preferably blocked and or is used for anend-to side or an end-to-end anastomosis. Alternatively or additionally,graft 38 is prepared so that it does not have a distal opening. Whenside to side anastomosis connections are made, graft 38 may havepre-formed holes in its side or holes may be made during the connectionprocess. In a preferred embodiment of the invention, each side of theside-to side anastomosis is individually patent, without requiringcompression of intervening tissue, as in some known methods.

FIGS. 2Q–2T illustrate methods and apparatus of forming a puncture in ablood vessel (aorta or coronary, i.e., from inside or from outside), inaccordance with preferred embodiments of the invention. In some of thedescribed embodiments, it is an object to avoid contact with portions ofthe blood vessel to be pierced, other than at or near the piecing area,to avoid damage to the blood vessel. One solution, is to provide apiercing tip which does not require a base to rest against.

FIG. 2Q illustrates a vibrating tip 310, for a guide wire 36, which maybe used for piercing a blood vessel in accordance with a preferredembodiment of the invention. Additionally, this tip may be used forpenetrating through a different type of layer, for example of softtissue, or even a hard tissue, such as a calcified aorta. In a preferredembodiment of the invention, tip 310 is made to vibrate rapidly in alongan axis indicated by an arrow 320 (and/or at another angle, such asperpendicular to the arrow), thereby piercing a blood vessel againstwhich it is placed. In a preferred embodiment of the invention, tip 310comprises a vibrating potion 314, a mechanical amplifier 316 and avibrating end 318. In a preferred embodiment of the invention,mechanical amplifier 316 has the shape of a horn (a cone) so that theamplitude of axial motion at the narrow end is about four or more timesgreater than at the wide end. In one exemplary embodiment, vibratingportion 314 comprises one or more layers of piezoelectric material,electrified by a wire 312. Amplifier 316 is formed of Titanium orAluminum and may have a base diameter of 3 mm. The surface of amplifier316 may be smooth. Alternatively, the surface may be rough, for exampleto engage tissue against which it vibrates and into which it isinserted. Alternatively or additionally, the surface may have formedthereon one-way barbs, so that tip 310 can easily enter by less easilyexit tissue.

Alternatively to piezoelectric vibration, other ways of generatingvibration may be provided, for example, resonant vibration responsive toexternally applied acoustic waves, transmitted through the tissue oralong the guide wire. Alternatively, magneto-strictive vibration may beachieved by forming vibrating portion 314 out of a suitable material andapplying an AC magnetic filed in the vicinity of portion 314.Alternatively, other vibrating methods may be used, for example using asolenoid. In a preferred embodiment of the invention, the frequenciesare between 5 and 50 Hz and the amplitudes are between 0.1 and 1 mm.Alternatively higher frequencies, for example between 50 Hz and 1000 Hz,higher amplitudes, for example between 1 and 3 mm, lower frequencies,such as between 1Hz and 5Hz, and/or lower amplitudes, such as between0.01 and 0.1 mm, may be used.

FIG. 2R illustrates a tip 322 which rotates as indicated by an arrow324. The rotation may be continuous in one direction, pulsed and/orreversing. Tip 322 is preferably threaded to engage the tissue intowhich it is inserted. The rotation is preferably provided by a motor326, which may be, for example, a magnetic motor or a piezoelectricmotor. Possibly, the motor is rotated using an externally applied ACmagnetic field, for example one caused by a rotating magnet. Therotation may be in addition to or instead of axial motion. Rotationalmotion may be achieved by making vibrating portion 314 not perpendicularto guide wire 36. U.S. Pat. No. 4,846,174 and PCT/US89/00261, thedisclosures of which are incorporated herein by reference, describemechanism which are useful for such rotating and vibrating tips.

Alternatively or additionally, to vibrating or rotating tips, a tip 37of a guide wire may be shot through the blood vessel, like a harpoon. Inone example, the tip is shot using a pneumatic or hydraulic pressurebuild-up in the guiding catheter. In another example, the tip is shotusing a suddenly applied magnetic filed which acts on a magnetic tip.Preferably, the motion of the tip is axially restrained, for example bya wire connected thereto, to avoid undesirable penetration of the tipinto non-local tissue.

FIG. 2S illustrates a process of clamping and piecing, in accordancewith a preferred embodiment of the invention. In an axial view of bloodvessel 30, a tip 37 is to penetrate the wall of vessel 30. One or moreclamping devices 330, for example a pair of pincers, pinch the wall ofvessel 30, so that a portion 332 is pinched inwards. A location 334,which it is desired to penetrate with tip 37, is preferably presented totip 37. Preferably, the orientation and/or position of clamping device330 is selected so that particular location is pierced. Alternatively,once clamped, the clamping may be removed, if the location is deemedunsuitable. In a preferred embodiment of the invention, tip 37 anddevices 330 are coupled, so that advancing tip 37 causes it to piercelocation 334. Once such piecing is confirmed, clamping device 330 may beremoved and the piercing process is completed. In some embodiments ofthe invention, tip 37 punches a hole (removing material) in vessel 30,rather than just piercing it.

FIG. 2T illustrates a process similar to that of FIG. 2S, in which thepiercing is performed from outside the blood vessel. Optionally, a tool340 aligns tip 37 against the blood vessel to guarantee that tip 37enters at a desired angle and/or orientation (angle from the plane ofthe figure). Alternatively, such guaranteeing is performed by clampingdevices 330.

FIGS. 2TA and 2TB illustrate a method of punching a hole in a bloodvessel, in accordance with a preferred embodiment of the invention. InFIG. 2TA, a tip 37 penetrates a wall of a vessel 30, such that a portionof the wall is grasped by an inner reduced diameter portion 550. Whentip 37 is retracted (relative to the rest of the catheter), as shown inFIG. 2TB, the wall is pinched and cut between an inner lip 554 ofportion 550 and a cutting base 552 of the guiding catheter. In apreferred embodiment of the invention, the hole into which tip 37 isinserted is formed by tip 37 itself. Alternatively, the hole may beformed by a special cutting guide wire, which can be retracted prior tothe advance of tip 37 or along which tip 37 rides.

In a preferred embodiment of the invention, the punched hole has acylindrical volume. Alternatively or additionally, the volume comprisesan oblique cylinder, with an elliptical cross-section at the vesselwall. Alternatively or additionally, the volume is conical.Alternatively, the volume is hour-glass shaped. Alternatively, thevolume comprises two base-to-base truncated cones.

In a preferred embodiment of the invention, one or more of a pluralityof measurements may be performed at the hole in the blood vessel. In oneexample, the thickness of the vessel is measured, for example using anultrasonic imager or distance or thickness sensor. Such a sensor (orother sensors described herein) may be provided at tip 37 or from aworking channel of an endoscope which assists in the anastomosis. Inanother example, the elasticity of the vessel is measured, for example,by applying a known force and/or a known displacement to the vessel wallusing a pressure transducer, and measuring the response (motion and/orpressure) at the transducer. In another example, the hardness of thevessel wall and/or reflections from it, are used to determine if thereis a calcification on the inside (or outside of the vessel. Thesemeasurements may be applied either or both from inside and from outsidea blood vessel. Alternatively or additionally, if a piezoelectricvibrating tip is used, such a tip may also be used to perform thesensing.

In a preferred embodiment of the invention, the sending is used todetermine a desired hole size to be punched. Desirably, the hole islarge enough so that the vessel is not unduly strained by the expansionof the hole and the hole is small enough so that the vessel walls willexert a pressure which aids in leak suppression and/or in holding theanastomotic connector in place. Possibly, a first, small hole ispunched, to assess the radial force applied by the wall, and if theforce is greater than desired (indicating undue strain on the vessel), alarger hole is punched.

In a preferred embodiment of the invention, the area of the punched holeis treated, for example, to prevent dissection of the vessel wall. Inone example, the circumference of the hole is coagulated, for exampleusing an electric field or a laser beam. Possibly, the coagulation isapplied at spots on the circumference. Alternatively, a continuouscoagulation is applied, for example by tip 37 itself being one electrodeof an RF coagulation circuit. Alternatively or additionally, the punchedhole is coated with tissue glue.

In a preferred embodiment of the invention, a drug may be applied to thepunched area, for example to assist in healing, to prevent dissectionand/or to assist in the hole punching process. In one example, the drugmay induce the dilation of corollary blood flow. In another example, thedrug may induce relaxation or expansion of the blood vessel, for exampleto stabilize the state of the blood vessel dilation or to assist inperforming the punch. Possibly, similar effects may be achieved byapplying low voltage electric currents to the blood vessel, to stimulatelocal relaxation or contraction.

In a preferred embodiment of the invention, an anastomotic connector ishollow. For example, the connector may be formed of two concentrictubes, with glue or a drug disposed between the tubes. When theconnector is radially expanded, the glue or drug can be forced out ofopenings in the surface or between the layers. Preferably, the openingsare at points whose final position relative to the anastomosis can berelatively guaranteed.

Alternatively or additionally, at least portions of the anastomoticdevice act as an RF antenna or as an eddy current generator, such thatwhen an RF field or an AC magnetic file dare applied (respectively), atleast the portions of the device heat and weld the anastomosis shut.

Alternatively to punching a hole in the blood vessel, a hole may be cutin the vessel by forming a circular cut-out. In one example, such acircular cut-out is formed by cutting along the circumference of thehole with a laser, a knife, a rotary cutter or an ultrasonic scalpel.Alternatively, the hole may be ablated, for example using RF ablation,micro-wave ablation or chemical ablation. Alternatively, a cutting toolmay be placed inside a hole and used to cut sideways into the vesselwall.

Alternatively or additionally to using percutaneous techniques, thenavigation, the final alignment with the artery (or vein) and/or theanastomosis to the artery (e.g., suturing) may be performed using akey-hole surgery technique. It should however be appreciated thatkey-hole surgery is aided by using the above described technique tobring, to a location adjacent a coronary vessel, a graft, one end ofwhich is already attached to the aorta. Thus, only a key-hole procedureat the anastomosis location (coronary and/or aorta) is required.

In a preferred embodiment of the invention, after the bypass isperformed, the graft is tested for leakage. Preferably, a contrast mediais injected and a fluoroscopic image is acquired after a short wait todetermine if any of the contrast material has leaked from the vascularsystem. In case of such leaks, the anastomosis may be strengthened, insome preferred embodiments of the invention, by inflating a ballooninside a leaking anastomosis connector to increase its contact with thewall of the vessel to which it is connected. Alternatively oradditionally, a stent and/or a graft may be inserted within the leakyconnector so that it is situated between the connector and the bloodflow. Alternatively or additionally, the leaking anastomosis may berepeated, by disconnecting the graft from the vessel, providing asuitable anastomosis connector and activating the provided connector, tocreate the anastomosis.

Alternatively or additionally, key-hole surgery is performed only at theleaking anastomosis, for example, to suture it.

Many variations on the technique described above may be performed,within the scope of preferred embodiments of the invention. In the abovedescription, tip 37 punches a pinhole (which is later enlarged) in aorta30 and vessel 22. Alternatively, tip 37 may be used to punch a hole of adesired size and/or cross-section, in aorta 30 and/or in vessel 22. In apreferred embodiment of the invention, the hole is smaller than thefinal anastomosis cross-section. Alternatively, the hole is ofapproximately the final diameter.

The above technique may also be used to connect other blood vessels, forexample, for femoral bypass or for a venous-arterial shunt. In addition,other body lumens may be connected, for example, in the intestines, inthe urinary tract, in the bile system, and/or in the respiratory system.

It should be appreciated that guide wire 36, even after it perforatesthe aorta, does not necessarily allow blood to leak from the aorta.Thus, in some preferred embodiments of the invention, the abovetechnique may be practiced, even if catheter 34 does not isolate hole 35and/or without stopping the heart and/or without reducing the systemicand/or local blood pressure. Alternatively or additionally, it may bedesirable to reduce the risk level so one of the above describedtechniques of reducing leakage from hole 35 and/or reducing theavailability of blood at hole 35, may be practiced.

The description of FIG. 2A suggests the desirability of using a “J”shaped catheter and/or pointing the guide wire in the direction oftarget point 28. However, it should be appreciated that graft 38 isnavigated in the body, possibly around obstacles (such as the heartitself). Thus, the initial direction of the guide wire exiting the aortamay be decided by other considerations, such as the location of thegraft along the aorta, the ease of repairing the anastomosis,interaction of the anastomosis size, location and angle with blood flowin the aorta and in the graft, and/or plaque location andarteriosclerosis of the aorta. Once the vessel is outside the aorta, itcan be guided to point 28.

In a preferred embodiment of the invention, a desired layout of graft 38is determined before starting the procedure. Such a layout depends notonly on the desirability of the end points, but also on the availablemaximum length of graft 38, the desire to minimize its length, availablelocations to attach the graft to anatomical structures, a desire tominimize the possibility of kinks and/or sharp bends in the graft, adesire to minimize the possibility of the graft getting pinched betweentwo anatomical structures and a desire to minimize the probability ofthe graft being pulled out of one of the blood vessels to which it isattached.

In a preferred embodiment of the invention, as shown in FIG. 21, graft38 may be used for a plurality of bypasses, for example, to bypass theentire left anterior descending coronary artery, especially if it hasmultiple occlusions. In a preferred embodiment of the invention, this isachieved using a plurality of side-to-side connections. Alternatively oradditionally, graft 38 may be forked or contain other types ofintersections allowing various legs of the graft to be attached atdifferent places. Alternatively or additionally, a second graft 38′ maybe pushed out of graft 38, after graft 38 is in place, possibly usingthe techniques described herein. Alternatively or additionally, aside-to end anastomosis may be performed between the two grafts eitherbefore or after the first graft is inserted into the body. Alternativelyor additionally, a side-to-side anastomosis is performed. When thesecond artery is at the “side” side of the anastomosis, the two ends ofthe second graft are preferably pushed out of the first graft together,until an anastomosis connector attached to the graft reaches the holethrough which the graft was pushed out. Then, the anastomosis ispreferably performed. It should however be appreciated that theprocedures described herein may be applied to substantially any coronaryartery.

As described herein, graft 38 is preferably provided through a bloodvessel. In an alternate preferred embodiment of the invention, graft 38is provided using other body organs as passageways, for example, usingthe lungs, intestines or other hollow organs. Alternatively oradditionally, the graft is provided via the body cavity itself, forexample, it is pushed into the body from the outside, via hole in theskin. In these embodiments, both of the anastomosis connections arepreferably performed from the graft into a target blood vessel. Theguide wire is preferably brought into the graft from a hole near itscenter and selectively guided to an end, depending on the end to begrafted. The hole may be patched, for examples, using methods describedherein or known in the art. Alternatively, the two end anastomosisconnections are performed using an endoscope which encloses or isparallel to the graft, without requiring a guide wire to pass throughthe graft at all. In one embodiment, the tip of the endoscope is usedfor piercing the blood vessel. The graft is inserted along the endoscopeor possibly in a groove therein and then the endoscope is removed,leaving the graft in the blood vessel. Possibly, the endoscope has adeformable cross-section, to assist in removal of the endoscope withoutshifting the graft from inside the blood vessel.

Alternatively or additionally, the anastomosis connections are performedby attaching two grafts, one to each target vessel, for example using aside-to-end anastomosis, and then performing an end-to-end anastomosison the free ends of the two grafts. Such an anastomosis may be performedpercutaneously, for example by providing a catheter through one of thetarget vessels. Alternatively or additionally, the end-to-endanastomosis may be performed using key-hole approach. It should howeverbe appreciated that a percutaneous approach is usually preferable tokey-hole surgery, since it causes even less trauma to the body. However,in some cases, a key-hole surgical procedure is required anyway, so thatit may be aided by a percutaneous procedure. Alternatively oradditionally, to a key-hole procedure, a transvascular procedure mayinteract with an endoscopic procedure, whereby a flexible endoscope isguided to a desired location in the body, adjacent where a transvascularprocedure is being performed.

FIGS. 2U–2W illustrate end-to-end anastomosis connections in accordancewith preferred embodiments of the invention. FIG. 2U shows a bloodvessel 342, possibly a coronary vein or artery having an occlusion 344.In accordance with some preferred embodiments of the invention, a bypassmay be performed between a pair of points 346 and 348 which are oneither side of occlusion 344. The bypass may comprise a graft whichattaches using a side-to end anastomosis at point 346 and an end-to-sideanastomosis at point 348, for example using the methods and apparatus asdescribed herein. Alternatively, an end-to-end inside anastomosis, asshown in the Fig., may be performed at one or both of 346 and 348.Alternatively, as shown for example in FIG. 2V, a graft 350 may beconnected to point 346 using an end-to-end anastomosis. The connectionat point 348 may be end-to-side (possibly oblique), end-to-end or anenclosed connection, in which graft 350 is inserted through the side ofvessel 342 and is bent so that it is coaxial with vessel 342. In apreferred embodiment of the invention, the end-to-end anastomosis atpoint 346 is achieved by expanding a guiding catheter (not shown,similar to catheter 302) to block the entire lumen of vessel 342 atpoint 346. Such an expandable catheter may for example include an outerballoon layer which can be radially expanded against vessel 342. Acutting tool is then extended through the lumen of the guiding catheterto sever (partially or completely) vessel 342. Then, graft 350 may benavigated out of the catheter to point 348, at which an anastomosis maybe formed. Similar navigation techniques as described herein may beused. Additionally, a guide-wire (not shown) may be provided to passocclusion 344, for example between the guide catheter and the wall ofvessel 344, prior to the severing, to mark location 348.

FIG. 2W illustrates a different type of end-to-end anastomosis which issomewhat similar to stent grafting. In this method, graft 350 does notexit vessel 342. Rather, a guidewire is passed through occlusion 344 andthe occlusion is expanded enough so that a graft can be passedtherethrough. In some cases the occlusion is so complete that it isnecessary to drill a hole through occlusion 344, for example using laseror a rotary ablator. In a preferred embodiment of the invention, vessel344 is sealed at or before point 346, so that if the seal of vessel 342is compromised by the expansion, no blood will leak out. Such sealingmay use balloons or an expandable catheter. Expanding anastomoticconnectors are then expanded at the two ends of graft 350, to completethe procedure. Alternatively, in FIGS. 2U and 2V, the seal at point 346may be formed by an end-to-end anastomosis between graft 350 and vessel342. After this graft is completed, the rest of the graft is advancedeither through the occlusion or around the occlusion. Typically, graft350 is folded or otherwise contracted so that it fits between point 346and occlusion 344. Alternatively, a first anastomosis is performed atpoint 348. Alternatively, graft 350 is inverted prior to insertion andis then un-inverted after the seal (or anastomosis) is made at point346.

Several distinctions should be noted between a stent and a connector inaccordance with some preferred embodiments of the invention:

(a) An anastomosis connector, in some preferred embodiments of theinvention, requires less contact with the blood than a stent, since itis mostly, if not totally, outside the blood vessel. For example, theembodiment of FIG. 8U would may be considered undesirable for use in astent, due to the large amount of surface area it has.

(b) The total area of contact between the connector and the bloodvessels is generally smaller, since the connector is not usuallyrequired to structurally support a significant portion of the bloodvessel.

(c) An anastomosis connector usually comprise less metal (per volumeand/or surface unit) than a stent, since the connector usually needs toprovides less support.

(d) An anastomosis device, in some embodiments described herein, is incontact mostly with the outside of the blood vessel, while a stent ismostly (or wholly) in contact with the intima. One reason for this isthat the blood vessel is everted for anastomosis, in some preferredembodiments of the invention.

(e) In preferred embodiments of the invention, an anastomotic devicegrasps a blood vessel from one or two sides, in a way that may preventdissection of the blood vessel. A stent usually only pushes against theblood vessel and does not engage the interior of the vessel wall, fromone or two sides.

Referring especially to FIGS. 2A–2G, in a preferred embodiment of theinvention, guide wire 36 has a tip diameter of, for example, 0.018inches and tapers slightly. When inserting the guidewire into vessel 22,preferably one, two or three centimeters are inserted into the vessel.The anastomosis connector has, for example, an outer diameter of about0.8 mm, in its closed configuration and is made of stainless steel witha thickness of between 0.1 and 0.2 mm.

The above description is generally applicable with respect to thevarious types of anastomosis devices used, in accordance with preferredembodiments of the invention, to connect graft 38 with vessel 22 and/oraorta 30. There are several considerations in selecting a configurationfor an anastomosis device, some of which are listed below. It should beappreciated that some of the considerations are have a greater effect onsome of the preferred embodiments, than other considerations.

(a) Bringing the two vessel together. In some preferred embodiments ofthe invention, the anastomosis device brings the two vessels closertogether.

(b) Non-desirability of leaks. In some preferred embodiments of theinvention, the anastomosis device provide a large area of contactbetween the two blood vessels, preferably completely surrounding theanastomosis connection. The probability of leaks occurring in thisembodiment is reduced. Alternatively or additionally, the connection maybe strengthened after the anastomosis connector is in place, inaccordance with some preferred embodiments of the invention.

(c) Non-desirability of vessel flaps remaining in the blood flow. Insome preferred embodiments of the invention, such flaps are trapped bythe anastomosis connection. Alternatively or additionally, the flaps arepushed out of the blood flow. Alternatively or additionally, such flapsnever come into existence, since the anastomotic connections are made bystretching a pin-hole, not by cutting a cross. A cross shaped slit or astraight-line slit may be cut using a guide wire with a suitably shapedtip. Alternatively or additionally, a sharp tip of the guide wire may beused to cut any desired shape by moving it along the surface of theblood vessel.

(d) A requirement to maintain a minimum cross-section of the anastomosisconnection. In a preferred embodiment of the invention, the anastomoticconnector comprises a ring portion, which maintains the connectioncross-section to be at least the inner diameter of the ring.Alternatively or additionally, the connection between the two bloodvessels is such that the configuration is not under tension or is undera minimal amount of tension when the anastomosis is open. For example,if the lips of the (expanded) pinhole are folded back the tension ismuch greater on the lips than if they are not folded back. Alternativelyor additionally, the blood pressure maintains the anastomosis open. Thefact that the anastomosis is on a major blood vessel, in accordance withsome preferred embodiments of the invention, aids in keeping it open.Alternatively or additionally, a portion of the “side” vessel is cutout, so that there is an opening therein which is covered by the “end”vessel.

(e) Desirability for a minimum amount of contact of non-endothelialsurfaces with the blood. This consideration includes both a desire tominimize the contact between foreign objects and the blood flow, and adesire that after the anastomosis is complete only endothelial surfacesof the blood vessels are in contact with the flow. Various connectors inaccordance with preferred embodiments of the invention, as describedherein, meet one or both considerations.

(f) Probability of the connection remaining leak proof for a long time.In a preferred embodiment of the invention, the anastomosis connectorprovides a tissue-to-tissue contact area, in which there is little or notissue necrosis. Thus, after a short while, a bridge is formed betweenthe tissues of the two vessels.

(g) Requirement to perform eversion of vessel tips, especially ifvessels are hardened or otherwise sensitive. Some types of anastomosisrequire a 90 degree or a 180 degree eversion of the vessels. Althoughthis usually results in a best connection, it may not be possible insome cases, for example if the vessels are hardened or prone tocracking. Some of the anastomosis connectors described herein requirelittle or no eversion. An additional benefit of not requiring eversionis a reduction in the difficulty in preparing the vessels foranastomosis. Preferably, only the graft vessel is prepared before theprocedure. The intra-body vessels cannot usually be prepared foranastomosis using percutaneous tools and in some preferred embodimentsof the present invention, need not be prepared.

(h) The number of pieces inserted into the body. There is usually adesire to minimize the number of object inserted into the body and/orthe blood stream, to minimize the danger of one of the pieces gettinglost or stuck. In some preferred embodiments of the invention, theanastomosis connector comprises a single piece, which is pre-attached tothe graft. Other embodiments utilize two or more pieces.

(i) The simplicity and speed of performing the anastomosis. In apreferred embodiment of the invention, the speed and simplicity of theanastomosis procedure are improved over those used in the prior art.

(j) The type of connection between the blood vessels. Various types ofconnections are provided in accordance with preferred embodiments of theinvention, as described above and as described below with reference toFIGS. 3A–3O. In particular, in some preferred embodiments of theinvention the anastomosis connection is an intima-to-intima connection.

(k) The type of force holding the vessel together. Various attachmentmeans are provided in accordance with preferred embodiments of theinvention, including, mechanically pushing the two contact surfacestogether, for example utilizing pins piercing both surfaces, glue,welding and/or plastic flowable material provided at and/or around theanastomosis connection.

(l) The strain on the blood vessel. The strains are mainly a result of ablood vessel being maintained in an unnatural configuration because ofthe anastomosis. In a preferred embodiment of the invention, the type ofstrain may be traded off with the type and/or quality of the connection.For example, strain may be a result of eversion. In a preferredembodiment of the invention, for a given procedure, no eversion isrequired, or eversion may be limited only to a blood vessel which cantake the strain. In some embodiments, strain may be the result ofstretching a pinhole in a “side” connected vessel. In a preferredembodiment of the invention, a larger hole may be made in this vessel toreduce the strain. In addition, strain may be a result of bending oreverting a blood vessel. Various types of eversions are provided for insome of FIGS. 3A–3O. In a preferred embodiment of the invention, some ofthe strain is carried by the anastomosis connector itself. Preferably,the connector is attached to the vessels at many points, so that thestrain may be divided over all the connections. In addition, if oneconnection fails, this does not necessarily mean the anastomosis willleak. Another type of strain is the result of the contact area beingsubstantially non-planar, as for example in a diagonal connection or inan end-to-side connection between two vessels of similar diameters.Preferably, the connector achieves a non-planar shape to conform to theshape of the contact area, thereby minimizing the tension on thevessels. Alternatively or additionally, the graft is precut to have anon-flat end, so as to reduce the strain on it.

In some cases, the long term strain is minimized. Alternatively oradditionally, the strain applied during the anastomosis is minimized.Alternatively or additionally, a tradeoff is achieved by which anacceptable strain is present. Preferably, the type of anastomosisperformed takes into account a maximum desired strain threshold.

(m) The requirement to provide the anastomosis connector through anarrow-diameter catheter lumen. In a preferred embodiment of theinvention, the connector is expandable and/or distortable, so that itmay be conveyed in a configuration which fits a desired lumen size.Alternatively or additionally, the connector comprises a plurality ofstaples or other local connectors and the connection is made using anexpandable anvil or framework which is brought through the lumen andexpanded to have a diameter larger than the cross-section of theanastomosis. Alternatively or additionally, the minimum diameter of thegraft with the connector attached may also be controlled and isdifferent for different types of connectors and/or connectionconfigurations. For example, configuration 82 in FIG. 4B can have asmaller diameter than configuration 80.

(n) Turbulence. The connection between the two blood vessels may causeturbulence, stagnation and/or clotting. In a preferred embodiment of theinvention, the angle and/or size of the anastomosis is selected tominimize turbulence. Alternatively or additionally, a connector typeand/or an anastomosis type is selected to minimize turbulence, forexample, by providing a low profile anastomosis connection.

(o) Blockage of the graft or the end-vessels. In a preferred embodimentof the invention, most or all of the anastomosis connection is outsidethe blood vessels, so that the flow of blood in the anastomosis area isminimally impeded. Alternatively or additionally, in large bloodvessels, a small portion of the cross-section may be sacrificed toachieve a better, faster and/or lower cost anastomosis.

FIGS. 3A–3O illustrate different types of side-to-end and end-to endanastomosis connections (with no connector shown), achievable inaccordance with preferred embodiments of the invention. FIGS. 3A–3HAillustrate end-to-side anastomosis connections. FIGS. 3I–3O illustrateend-to-end anastomosis connections. Typically, an anastomosis connector,as described below, either will pierce the blood vessels on both sidesof the contact area or will follow the contour of the contact area.Alternatively, the connector may be completely outside the bloodvessels. FIG. 3P illustrates a side-to-side anastomosis, incross-sectional view, in accordance with a preferred embodiment of theinvention. In a preferred embodiment of the invention, an anastomoticconnector, for example similar to the connector shown in FIG. 4A isprovided, for example using a system as described with reference to FIG.8. Alternatively, the tip of the connector is threaded and the connectoris rotated to engage and hole the side of the enclosing vessel.

FIG. 4A illustrates a one piece anastomosis connector 60, in plan view,in accordance with a preferred embodiment of the invention. Connector 60preferably includes a first spike section 64, a central section 61 and asecond spike section 66. Preferably, the central section comprises aplurality of parallelograms 62. When installed, central section 61 ispreferably closed, for example, by overlapping at the two lines marked“A”. This closing may be by manual welding, supplying a connector or byconnector 60 being formed as a cylinder. Alternatively or additionally,connector 60 is formed to naturally assumes a cylindrical shape.Alternatively or additionally, connector 60 is simply rolled into acylindrical shape, without the two sides being connected. Although twospike sections, one at each side of the device have been described, inother preferred embodiments of the invention, a fewer or a greaternumber of spike sections may be provided, for example, one, three, fouror five. Alternatively or additionally, the spikes in a spike sectionmay be arranged in bands around the circumference, in axial bands, ingroups and/or in other arrangements. Alternatively or additionally, thespike sections may be formed in the center of the connector or incentral section 61.

In a preferred embodiment of the invention, all the parallelograms 62are of equal size. Alternatively or additionally, they are not all thesame size and/or shape, for example to better control the final geometryof the connector or the deployment of the spikes. In a preferredembodiment of the invention, section 61 comprises a plurality of bands,each of which has a different parallelogram size and/or shape, forexample for providing an hour-glass or a tapered profile. The bands maybe radial. Alternatively or additionally, the bands are axial, forexample, to control particular spikes provided along or at an end of theband. Alternatively or additionally, a different spatial distribution ofparallelograms is used. The spikes may be connected at outer vertexes 72of section 61. Alternatively or additionally, some or all the spikes ofat least one of the sides are connected to inner vertexes 74. The ratiobetween an axial radius 70 and a radial axis 68 of the parallelogram ispreferably a controllable property of the device.

Connector 60 may be formed to have elastic tensions in portions thereofso that it has a resting shape other than that of a cylinder.Preferably, connector 60 comprises a super-elastic, elastic and/orshape-memory material. While being deployed, connector 60 is preferablymaintained in a desired geometry using mechanical restraints.Alternatively or additionally, connector 60 is formed of a shape-memoryalloy, which is activated when the connector is deployed. Alternativelyor additionally, at least portions of connector 60 are formed of aplastic material, which is plastically distorted, for example by aballoon, into a desired configuration. These different elasticcharacteristics may be combined in a single device. For example, thespikes may have a super elastic, elastic or shape-memory tendency tofold out and grab tissue and the cylinder may be super elastic, elasticor shape-memory, so that when relived of constraints, it expandsradially slightly, thus providing room for a balloon to be insertedtherein. The rest of the deformation is preferably provided by plasticdeformation. Alternatively or additionally, some portions of connector60 may be specifically made weaker so that any plastic deformation tendsto concentrate at those locations. Thus, it is possible to predeterminewhere connector 60 will bend, when inflated by a balloon, for example.

In a preferred embodiment of the invention, connector 60 is formed of astainless-steel central section 61 welded to super-elastic orshape-memory spikes (e.g., NiTi). Possibly, the spikes are formed with aring, possibly containing whole or partial parallelograms, which ring iswelded to section 61. Possibly, the connector is cut, preferably using alaser, after it is welded. Alternatively or additionally, the connectoris first welded then cut. Alternatively, the connector is all formed ofa super-elastic, elastic and/or shape-memory material, which material isannealed at portions thereof, for example at central section 61, to nothave an innate tension. Alternatively or additionally, the material isannealed to make is a more plastic material.

In some preferred embodiments of the invention, connector 60 is, atleast to some extent a passive device, whose final geometry isdetermined by external considerations, such as by a balloon whichexpands the connector or by additional shaping elements which may beprovided at the connector during deployment thereof. Alternatively oradditionally, connector 60 is, at least to some extent, an activedevice, for example being composed of shape-memory material. In anactive device, the forces that determine the devices shape arise fromthe device itself Typically however, some control over the device'sfinal configuration, can be exerted by providing suitable restrainingelements while the device is being deployed.

In a preferred embodiment of the invention, connector 60 is an assistivedevice, whose passive responses to external forces and/or activity as aresult of internal forces are directed towards assisting the anastomosisprocess as a whole and/or particular steps thereof. An assistiveanastomosis device preferably aids the anastomosis process in one ormore of the following ways:

(a) Grasping tissue so it does not move during critical steps of theanastomosis.

(b) Everting and/or guiding the eversion of one or both vessel so that adesired type of intima contact is achieved.

(c) Exerting pressure between tissue portions, especially to stop bloodleakage.

(d) Aligning of the connector and/or the blood vessels. One particulartype of alignment is self-centering of the connector in the aorta.

(e) Tightening. One type of tightening assistance is tighteninglimitations, to avoid over-tightening of the device during deployment.Another type of tightening assistance is self tightening, so that thedevice does not become loose during the time after it is implanted and.

(f) Deployment of the connector in steps, rather than as a continuum. Insome preferred embodiments of the invention, the deployment of thedevice is in clearly defined steps. Thus, the results of each step canbe checked for suitability. Also, a single step can be undone and oradjusted, if necessary. Further, the treating physician can work at aslower pace, if necessary. Alternatively or additionally, the tissue hastime to achieve a steady state between steps, allowing better controlover the deployment. One example of a step-by-step deployments is iffirst the front spikes extend, the extension (when completed) releasinga restraint which allows the connector to expand, thereby causing axialshortening. The restraint may be released, for example, by a base of thespike moving or twisting.

(g) Piercing and expanding holes in blood vessels. In a preferredembodiment of the invention, the end of connector 60 (when un-expanded)can serve as a tip for piercing a blood vessel. Alternatively the end ofconnector 60 can serve as a device (possibly a punch or a portionthereof, such as the outer tube) for cutting out a portion of the vesselwall. Alternatively or additionally, connector 60 may expand inside thehole thereby increasing its radius.

In a preferred embodiment of the invention, the maximum radial expansionin the center of the connector is smaller than at it upper or lower(axial) ends. Thus, when inflated it will assume an hour-glass form, sothat it holds better. Such a form may also assist in everting the tipsof the graft and/or the aorta. Also, such a form may assist inself-centering of connector 60 in the hole made in the side of aorta 30.Alternatively or additionally, the connector is made stiffer at itscenter, so that when inflated by an elastic balloon, the connector willtend to expand more at its ends that at its center. In a preferredembodiment of the invention, different levels of stiffness may beachieved by varying the shape of the parallelograms and/or the thicknessof the sides and/or by surface treating portions of the connector and/orby heat-treatment of portions of the connector and/or by using specialcoatings on portions of the connector.

In a preferred embodiment of the invention, the connector is notsymmetrical in its final configuration, around its axial axis and/oraround a radial line. In one example, the lower portion has a maximalradial expansion higher than the upper portion. In a preferredembodiment of the invention, this asymmetry matches characteristics ofthe connection type and/or the relative sizes of the blood vessels. In apreferred embodiment of the invention, the parallelogram's sizes andstiffness' are varied so that the connector everts over itself, possibly90 or 180 degrees and/or assumes the shape of a top-hat, with a “T”cross-section. This type of connector may be used as a “T” shaped patchto patch a failed side-to-end anastomosis. Alternatively oradditionally, this type of configuration is used for everting a “side”interface of an anastomotic connection.

In a preferred embodiment of the invention, element shapes other thanparallelograms are used; for example, other four-sided shapes,pentagons, hexagons, circles and/or arbitrary shapes formed of straightlines and/or curved lines. In a preferred embodiment of the inventionwhere a triangular shaped element is used, preferably one of the sidesof the triangle is pre-formed so that when it is distorted it folds outto engage tissue and does not fold out into the blood stream.

In a preferred embodiment of the invention, connector 60 is radioactive,preferably, to retard intimal growth. Preferably, the level ofradioactivity is not constant along the length of the connector.Preferably, portions of the connector which are at or near the contactbetween the two blood vessels are not radioactive. Alternatively oradditionally, only portions of the connector which are in contact withthe blood are radioactive. Alternatively or additionally, the spikes arenot radioactive, at least in portions thereof which engage the vesselwalls.

Alternatively or additionally, the resting form of connector 60 is not asimple cylinder. In a preferred embodiment of the invention, theconnector naturally assumes a form shown by one of the cross-sections inFIG. 4B, below. Alternatively, such a shape may be dictated by asuitably shaped anvil-balloon, against which the connector is expanded.

One characteristic of some preferred embodiments of the connector shownin FIG. 4A, is a coupling between radial expansion and axialcontraction. In a preferred embodiment of the invention, when connector60 is expanded in a radial direction, it contracts in an axialdirection. An example of this relationship is illustrated in FIGS. 4B–4Dthat show different amounts of radial expansion.

FIG. 4B shows in cross-section two possible starting configurations, 80and 82, for mounting a connector 60 on a graft 38. In bothconfigurations, spikes 66 are bent and spikes 64 are bent to engage thegraft. However, in configuration 80, spikes 64 conform to the outside ofthe eversion of the graft, while in configuration 82, spikes 64 piercethrough the everted portion of the graft. Typically only one ofconfigurations 80 or 82 will be used in any particular connection. Insome cases however, both configurations may be used in a singleconnector.

In FIG. 4C a wall of aorta 30 is shown in cross-section, where it is notyet engaged by spikes 66. This configuration is preferably achieved bypushing the configuration of FIG. 4B out of the aorta, along a guidewire, until the everted part of graft 38 comes into contact with theaorta, as shown in FIG. 4C.

FIG. 4D shows the result of expanding a balloon inside graft 38. As aresult, the inner radius of connector 60 increases. Simultaneously, thehole in aorta 30 may also be expanded. Also simultaneously, connector 60experiences an axial contraction, which urges spikes 66 into the aortaand which forces together the everted portion of graft 38 and aorta 30.In this anastomosis two surfaces which are forced into contact areindicated in FIG. 4D as 84 and 86 respectively, namely (i) the aorta andthe side of the graft and (ii) the inside of the aorta and the evertedportion of the graft. Although connector 60 runs along one(configuration 82) or both(configuration 80) of these surfaces, there isa large amount of tissue-to-tissue-contact, since the connector ispreferably not a solid surface.

As can be seen in FIGS. 4B–4D, various types of spikes and spikedeformations may be practiced in accordance with preferred embodimentsof the invention. The spikes may extend at an angle to the surface of,for example, 45°, 90°, 135° 180° (parallel with an offset) or 270°.Typically, the spikes are extended at one angle (possibly 0°) beforedeployment and the deployment changes the angle. The deployment of theconnector may deform the spikes in several ways: the spikes may bend anadditional amount, for example 45 or 90 degrees; and/or the spikes mayextend in a same direction, for example as spike 66 does in FIG. 4D. Inaddition, the axial shortening of the connector may also affect theposition of the spikes, effectively shortening or lengthening them. Ascan be appreciated, a single connector may utilize a plurality of spikeangles and deployment methods, possibly in a non-symmetric manner. Thedirection of the spike deformation can be axial, perpendicular to theconnector surface, parallel to the connector surface or a combinationthereof. Some ways of achieving perpendicular deployment are describedwith reference to FIGS. 7C–7N.

In a preferred embodiment of the invention, connector 60 has anon-constant thickness. In a preferred embodiment of the invention, thenon-constant thickness is used to provide varying amounts of elasticityand plasticity to different parts of the connector. Alternatively oradditionally, increases in thickness, for example as shown at locations88 in FIG. 4D, possibly comprising a ring around the connector, are usedto provide a better seal against blood escaping the anastomosis.

FIG. 4E is a plan view of an anastomotic connector 360, in accordancewith a preferred embodiment of the invention. Several features areillustrated in connector 360, not all of which are required in a singleconnector. A first feature is wires 362 which interconnect spikes 361 ofthe connector. These wires limit the maximum expansion achievable by thespike portion of the connector. Alternatively or additionally, thesewires stop spikes 361 from digging too deeply into the blood vessels. Ifthe spikes dig in deeply enough, the blood vessel will contact theparallelograms, which being “V” shaped at the point where they contactthe spikes, could mangle the blood vessel. In some preferred embodimentsof the invention, the “V” shaped expansion at the base of spikes may beused to slice through a graft which is transfixed on the spikes, byexpanding the radius of the connector such that the graft is forced toexpand over the base of the spikes and be cut.

A second feature is struts 364 that form smaller parallelograms at thebase of the spikes. These struts can serve the purpose of allowing alarger number of spikes than parallelograms in a circumference. Anotherpurpose they can serve is limiting the radial expansion of the spikearea, thereby limiting the expansion of the anastomosis opening, forexample so avoid ripping the graft by over expansion, while allowing therest of the connector to expand to a radius greater than that of thegraft, if necessary. Another purpose they can serve is as a stop to stopthe vessel from destroying itself on the parallelograms. The terms“wires” and “struts” as used herein are used to differentiate betweenthe functions of two structural elements: wires apply tension, whilestruts can withstand compression and torque, to some extent. Both strutsand wires may be connected between spikes, parallelogram sides, and/orparallelograms vertices. Additionally, struts and wires may be connectedparallel, perpendicular or at a different angle to the connector axis.

A third feature is a tissue block 366, which can serve to prevent theblood vessel from slipping off the spikes. A fourth feature is a tissueblock 368, which limits the advance of the blood vessel along the spike.The two types of blocks (and/or any of the above features) can be usedin conjunction, to define an area of the spike within which the vesselwill come to a rest.

FIGS. 4F–4I illustrate anastomosis connectors which require a minimumamount of physician intervention, during deployment, in accordance witha preferred embodiment of the invention.

FIGS. 4F and 4G illustrate a connector 558, in which one set of spikes562 is formed into a tip 560, which tip is used to penetrate vessel 30.In FIG. 4F, connector 558 is shown before expansion and in FIG. 4G,connector 558 is shown after expansion and the completion of theanastomosis.

In a preferred embodiment of the invention, connector 558 is plasticallyexpanded using a balloon 566. Alternatively, connector 558 is formed ofa super-elastic, elastic or shape-memory material which distorts byitself into the form shown in FIG. 4F. In a preferred embodiment of theinvention, tip 560 is maintained by a guide wire (not shown) whichengages rings or hooks (not shown) on the inside of spikes 562. Whenthis guide-wire is retracted, the spikes can bend, for example into thegeometry shown in FIG. 4G. Alternatively, spikes 562 are in a bi-stablestate (as described below), in which the spikes can either be in theform of a tip 560 or in the form of individually deployed spikes. In apreferred embodiment of the invention, spikes 562 are moved from astable state by the force applied by vessel 30 against tip 560 oragainst the base of the spikes. Alternatively, the stable state may beunbalanced by a partial inflation of a balloon inside tip 560, byallowing expansion of connector 558 or by applying force against tip 560from inside the connector.

In a preferred embodiment of the invention, tip 560 has a step profile,as indicated by reference 568, which limits the advance of tip 560 to adesired penetration depth, at which the expansion of the connectpreferably has the desired effects. Force against this step may alsodislodge the restraining wire and/or upset the stable state in abi-stable spike configuration. Alternatively, the profile is acontinuous profile. Preferably, tip 560 is smooth. Alternatively oradditionally, tip 560 comprises barbs (to prevent retraction) and/or isat least partially threaded.

In some preferred embodiments of the invention, device 558 is used foran oblique anastomosis. In a preferred embodiment of the invention, stepprofile 558 is oblique, to support an oblique hole mailing.Alternatively or additionally, the cross-section of tip 560 has anon-circular which is not centered on its axis, for example the tiphaving the geometry of an off-center cone, so that a non-obliqueinsertion angle presents less resistance than a perpendicular one.

Alternatively or additionally, an external restraining sleeve 570 isprovided. In a preferred embodiment of the invention, sleeve 570includes one or more protrusions which are forced back by contact withvessel 30. When these protrusions move back, the restraint of sleeve 570is lessened or removed, allowing the connector and especially tip 560,to expand.

FIGS. 4H and 4I illustrate a connector 572, in a restrainedconfiguration and in an expanded configuration, respectively. Forwardspikes 574 of connector 572 are preferably restrained by a hollow tip576, which can also be used for penetrating the wall of vessel 30. Backspikes 578 are preferably restrained by a sleeve 582. In FIG. 4Hconnector 572 is shown after insertion into vessel 30. In a preferredembodiment of the invention, the advance of connector 572 is limited byone or more arms 580 (or a ring) which protrudes from connector 572(shown only in this Fig.). Alternatively or additionally, the advance islimited by a protrusion 584 from the restraining sleeve, through whichsleeve the advancing force is applied (shown only in this Fig.).Alternatively or additionally, the advance is limited by connector 572having an hour-glass shape or by a widening of the back of the connector(not shown).

In FIG. 4I, tip 576 has been advanced, releasing forward spikes 574 toengage the vessel. Sleeve 582 has been retracted to release back spikes578, to also engage the vessel.

In a preferred embodiment of the invention, if the deployment of thedevice is not satisfactory, the device may be expanded using a balloon.Preferably, the device has a temperature transition for losing itselastic properties at about body temperature. Thus, a few seconds afterthe connector is inserted, it behaves, at least in part, as a plasticmaterial.

As can be appreciated, some of the devices described herein may beapplied in a one- or two-step process, in which a physician has only toadvance the connect/graft against a blood vessel to perform ananastomosis. It should be noted that the device of FIG. 4F (in someembodiments thereof, for example super-elastic embodiments) may also beapplied without an object in the lumen of the graft, thus being suitablefor both sides of an anastomosis, for example in key-hole surgery.Additionally, the anastomosis process is preferably fast enough so thatit may be performed even with a beating heart, even on an aorta, with alow a risk of hemorrhage.

FIG. 5 is a graph illustrating various possible relationships betweenradial expansion and axial contraction in anastomosis connector 60,achievable using different angles for the parallelograms and/or variousstruts, wires and/or ratchet mechanisms, described below. As shown inFIG. 5, both positive and negative couplings are possible. In addition,the coupling may be dependent on the instant radius of the connector.Thus, in a fully inflated configuration, additional inflation will notprovide much additional axial contraction. A reference number 85indicates a positive, decreasing coupling, where increasing the diameterincreases the axial dimension, however, to a lessor degree as the radiusincreases. A reference number 87 indicates a negative, constantrelationship, whereby increase in radius always decreases the axialdimension. A reference number 89 indicates the coupling described above,whereby a large axial shortening is achieved when the radius is smalland a small axial shortening is achieved when the radius is large.References 81 and 83 indicate non-monotonic coupling, where the decreasein axial dimension is relatively constant over a “working range” of thedevice.

In a preferred embodiment of the invention, the spikes are not straight(as shown in FIG. 4A). In a preferred embodiment of the invention, thespikes are tapered over a considerable portion of their length.Alternatively or additionally, the spikes are jagged. Alternatively oradditionally, the spikes have an inverse taper or are barbed, so thatthey form a more stable connection. Alternatively or additionally,instead of spikes, the “spike” portion is a relatively continuessurface, such as a band, which surface can evert in a manner similar toa rivet, and thereby engage the blood vessel.

In a preferred embodiment of the invention, the lumen of the anastomoticconnection is circular. However, in some preferred embodiments of theinvention, a non-circular connector lumen may be preferred, for examplean oval lumen, a polygonal lumen or a figure “8” lumen. Alternatively oradditionally, the diameter and/or geometry of the lumen may vary alongthe lumen. The outside form of the connector is generally the same asthe lumen. However, in some embodiments, the outside of the connectormay include protrusions or may have a different geometry (and thusvarying thickness) than the lumen. In some embodiments of the invention,the center of the lumen lies along a curved or piece-wise line. Such anembodiment may be useful for inducing certain desired flow patterns inthe flow at the anastomosis connection. Alternatively or additionally,the inner surface of the lumen includes protrusions for forming such adesirable flow pattern.

In some case, it may be desirable for the anastomosis connection to beoblique, for example to provide betted blood flow dynamics. An obliqueconnection may be additional or alternative to the use of a non-circularlumen cross-section (cross-section measured perpendicular to the endvessel main axis).

FIG. 4J illustrates an exemplary oblique anastomotic connector 579 intop, isometric and side views thereof. FIG. 4K illustrates connector579, as deployed in a completed oblique anastomosis. It should beappreciated that many of the connectors described herein may be madeoblique by varying their structure. In some cases, it may be desirableto match the spike lengths and/or extension to the oblique angle of thedevice, to prevent damage to the blood vessels.

FIGS. 6A and 6B illustrate an alternative one piece anastomosisconnector 90, in accordance with a preferred embodiments of theinvention. In FIG. 6A the connector is shown in plan view, in acompressed configuration. Dots 92 indicate short spikes which arepreferably used to engage the blood vessels. In a preferred embodimentof the invention, however, the connector will be attached to graft 38,as shown in FIG. 6C, prior to inserting the graft into the body.

When inflated and/or allowed to return to a resting condition, some ofthe spikes and the band to which they are attached fold up and some folddown, resulting in the configuration of FIG. 6B, which illustratesconnector 90 in its final configuration. FIGS. 6C–6E illustrate steps inachieving this configuration.

In FIG. 6C, connector 90 is mounted on a graft 38. A plurality of innerarms 96 are inside the graft, a plurality of spikes 94 on the arms donot engage tissue and the graft itself is not everted. The arms maycomprise substantially rectangular pieces. However, In a preferredembodiment of the invention, the arms comprise a Gaussian-like (orhalf-sine-wave) portion of metal which has a spike at its tip. Thus,connector 90 preferably has a smooth outline. In FIG. 6D, the graft isexpanded, for example using balloon or relaxing a constraint on asuper-elastic, elastic or shape-memory connector 90, so that arms 96bend out and the graft becomes everted. In FIG. 6E, either the expansionis continued or connector 90 is squeezed against a balloon, so thatspikes 94 engage the aorta. Connector 90 may be squeezed for example, byproviding one balloon on each side of the connector and inflating theballoons. Alternatively or additionally, the body of a catheter (notshown) may provide an anvil against which connector 90 is compressed.

In the example of FIGS. 6A–6E, the connector supports a multi-stepconnection process, in which each additional inflation further modifiesthe shape and/or configuration of the connector and advances a step ofthe connection, i.e., engaging the graft, everting the graft and finallyengaging the aorta. Each one of these steps may be mediated and/orassisted by a different part of the connector.

In a preferred embodiment of the invention, a different type ofconnector is provided, formed of a soft material, for example silicone.This connector comprises a tubular portion, which engages either theinside or the outside of the graft and one or more leaves which fold outagainst the inside of the aorta. In a preferred embodiment of theinvention, these leaves include barbs which engage the aorta.Alternatively or additionally, the tubular portion includes a depressionwhich engages the cross-section of hole 35 (FIG. 2A). Alternatively oradditionally, the tubular section includes a ring, embedded in the softmaterial, which maintains the cross section of the hole 35 and/or inwhich the depression is formed, so the connection does not slip. In someembodiments, no leaves are required.

In a preferred embodiment of the invention, the soft material comprisesa graft material, preferably a biological graft material, inside ofwhich an expandable ring is embedded. Alternatively or additionally, thegraft is everted 180 degrees over such a ring. The everted portion ofthe graft is inserted into the hole in aorta 30 in a compressed form andwhen it is expanded it opens the hole and the graft-covered ring engagesthe walls of aorta 30, in a groove along the outer rim of the ring.

FIGS. 7A–7B illustrate a pin based ring anastomosis connector 100, inaccordance with a preferred embodiment of the invention. FIG. 7A showsconnector 100 in a radially compressed configuration. Dots 102 indicatespikes. Connector 100 may be used by itself to affect anastomosis.Alternatively or additionally, connector 100 may be used with a second,possibly similar ring. FIG. 7B shows connector 100 after it is deployed,in conjunction with a second ring 108. Spikes 104 of ring 100 engagepre-formed holes 106 in ring 108. Alternatively or additionally, spikes104 may be longer than shown and fold back after piercing graft 38 andaorta 30. Thus, a second ring may not be required, although one may beprovided as a base for the folded back spikes. Preferably, the rings arefolded back against an anvil, for example an inflatable balloon or acollapsible ring structure which is urged against the spikes for bendingthem and then removed from the body.

In a preferred embodiment of the invention, both rings 100 and 108include spikes and pre-formed holes. Alternatively or additionally, atleast one of the rings has only spikes or only holes. Alternatively oradditionally, to holes 106, ring 108 may have formed therein a groove ora plurality of closely-set holes which spikes 104 may engage withoutaligning the two rings. Alternatively or additionally, spikes 104 engagea piercible friction material, such as silicone, which holds the spikes,for example by friction, instead of or in addition to holes 106. Theentire ring or portions thereof may be formed of the friction holdingmaterial Alternatively or additionally, the friction holding materialmay comprised in a layer on top or below a non-piercible portion of thering. In a preferred embodiment of the invention, spikes 104 are jagged,to better engage the friction material.

FIGS. 7C–7N illustrate various mechanisms for extending spikes out of asurface of the anastomotic device, in accordance with a preferredembodiment of the invention. Alternatively or additionally, thesemechanisms may be used to control other aspects of the connectors' finalor intermediate geometry, for example internal radius, shape and/orlocal variations in the geometry, such as the provision of ratchetmechanisms and/or other mechanisms which lock the spikes and/or thefinal connector geometry.

FIGS. 7C and 7D illustrate a strut based system in which a strut limitsthe distortion of a parallelogram. However, when the parallelogram isdistorted, so that its width (perpendicular to the connector axis)increases, its length, or at least the distance between the top andbottom vertices, must decrease. As the strut is non-compressible, butbendable at a designated portion thereof, when the parallelogram widthis increased by the expansion of the connector, the parallelogram bendsout of the plane of the connector so that the two vertices which areconnect to the strut come together. FIG. 7C illustrates a connector 370having two bands 372 in which some or all of the parallelograms includeaxially-disposed struts 374 which limit the axial extension and/orshortening of the parallelogram. A smaller or larger number of suchbands may be provided. Additionally, bands, or individualstrut-including parallelograms may be provided at other parts of thedevice, for example for spikes which are in the middle of the device orto cause the device to have bumps. In a preferred embodiment of theinvention, the parallelograms themselves serve as the spikes.Alternatively or additionally, extensions of the parallelograms, forexample a spike 375 may be provided.

FIG. 7D is a table illustrating front, side and top views of a singleparallelograms, a cross-sectional view and a complete connector 370,respectively, in a state before deployment and in a state afterdeployment. A weakening 376 is shown in a middle (or other desiredpoint) of strut 374, to promote bending of strut 374 at that particularpoint. In addition, a weakening may be selectively applied to theoutside of the inside of connector 370, to promote inward or outwardfolding. Alternatively, the direction of folding is determined by aballoon which is inside the connector when it expands.

FIGS. 7E and 7F illustrate a connector 380 in which spikes are extendedby a change in surface geometry of the connector. As shown in FIG. 7E,the connector has a radius R2 and a smaller radius R1, where the smallerradius is at portions of the connector which are distorted inwards. Aplurality of spikes 384 are each connected to a base plate 382. In theembodiment shown, the spikes are generally perpendicular to the baseplates and the base plates are parallel to the connector surface.However, due to the distortion of the connector, the surface, at leastin the area of the base plates is substantially perpendicular to the acircle enclosing the connector, so the spikes do not extend from thesurface. Once the connector is expanded, as shown in FIG. 7F, thesurface of the connector (at least in the areas of base plates 382) isparallel to the enclosing circle and the spikes extend.

FIG. 7G illustrates a connector 390 similar to connector 380 of FIGS. 7Eand 7F. However, instead of the surface of the connector beingnon-circular, as in FIGS. 7E and 7F, a plurality of base plates 394 arenot parallel to the surface of the connector. Instead, base-plates 394protrude into connector 390. A plurality of spikes 392 are attached tothe base plates at an angle, preferably being perpendicular, but in somecases, a smaller angle, such as less than 70°, less than 60° or lessthan 40°, may be desired. When a balloon is expanded inside connector390, the base-plates are urged against the sides of connector 390, sothat they are substantially parallel to the surface. Thus, spikes 392are extended.

In some preferred embodiments of the invention, at least some of thespikes are extended super-elastically, or elastically, for example bythe spikes being made of a suitable material (e.g., super elastic) or bythe spikes being connected to a base formed of a suitable material(e.g., super-elastic). The super-elastic or elastic portion is “trained”to a configuration where the spikes are extended and then the spikes arecollapsed and restrained. When the connector is deployed, the restraintsare relaxed and/or removed and the spikes return to their previousposition. Alternatively to super-elastic materials, the spikes or theirbase may be formed of a shape-memory material. During deployment, thespikes are preferably heated to above the transition temperature andthey extend. Possibly, the transition temperature is below the bodytemperature. Alternatively, the connector is heated, for example using aheated balloon or by radiating radiation, such as RF or ultrasound, atthe connector.

FIG. 7H shows a super-elastic, elastic or shape-memory connector 396 ina collapsed configuration, in which a plurality of spikes 392 areradially collapsed. FIG. 71 shows the same connector after the spikesextend radially.

FIG. 7J shows a super-elastic, elastic or shape-memory connector 400 ina collapsed configuration, in which a plurality of spikes 402 areaxially collapsed. FIG. 7K shows the same connector after the spikesextend axially.

FIGS. 7L and 7M illustrate a geometry in which the connector itselfforms a restraint to prevent the extension of the spikes. When theconnector is distorted, for example as a result of expansion therestraint is released and the spikes extend.

In FIG. 7L, a parallelogram 404 is shown in a front and a side view. Theextension of a spike 406 is restrained by the body of the parallelogram.When parallelogram 404 is distorted in the direction of an arrow 408,the restraint is released, (because the spike is shorter than the newdiagonal of the parallelogram) and the spike can extend, as shown forexample in FIG. 7M.

FIGS. 7P–7R illustrate a two stage folding of a pair of spikes, inaccordance with a preferred embodiment of the invention.

FIG. 7P illustrates a schematic connector 600, having a singleparallelogram band with a spike at each end. Each parallelogram isformed of at least a first, outside parallelogram 604 and at least oneinner parallelogram 602. For simplicity, two spikes are shown extendingfrom the parallelogram, each spike being formed by an inner extension610 and an outer extension 608 which combine at a tip 606 of the spike.In addition, a plurality of weakenings 612 are preferably provided alongthe spike. As can be noted from the figure, the angles of innerparallelogram 602 are different than from outer parallelogram 604. Thus,when the parallelogram is radially expanded, inner parallelogram 602 isdistorted more. As a result, extension 610 shortens more than extension608, causing the spikes to fold (shown in FIG. 7Q, possibly in a mannersimilar to a human finger). As the radial expansion continues, outerparallelogram 604 is also distorted, causing the spike to bend some more(shown in FIG. 7R). Alternatively to two parallelograms, three or moreconcentric parallelograms can be provided. In some preferred embodimentsof the invention, asymmetric geometric shapes are used instead of theparallelograms, which shapes may be different for the inner and outerelements and/or be oriented differently, so that other bending effectscan be achieved.

FIGS. 7S–7T illustrate a connector 612 with cantilevered spikes 614, inaccordance with a preferred embodiment of the invention. For anindividual parallelogram 622, a spike 614 is attached at one end to aninner vertex 618 and somewhere along its length to a lever 616, which isattached to an outer vertex 620 of the parallelogram. When theparallelogram is radially expanded, it axially shortens, until the spikeis bent by lever 616 to be perpendicular to connector 620. By providinga plurality of levers 616 at different points along spike 614 (possiblyeach lever attached to a different size and/or shaped parallelogram),other bending effects can be achieved. The end of spike 614 ispreferably pre-bent to a certain angle. FIG. 7T showsside-cross-sectional views of connector 612, during deployment. Areference 624 shows connector 612 prior to radial expansion, a reference626 shows an intermediate state and a reference 628 shows a finaldeployment state.

In a preferred embodiment of the invention, a spike may exhibit two ormore extension steps by each extension step utilizing a differentmechanism and/or a different triggering. In one example, a firstextension step is by super-elastic restoration (triggered by releasingof a restraint) and a second extension step is by twisting of the spikebase by radial expansion of the connector (triggered by expansion of theconnector).

Alternatively or additionally to super elastic and shape memorymaterials, the spikes or their base may be formed of a bi-metal whichdistorts as a result of body heat. Alternatively to using two dissimilarmetals, one of the “metals” may be formed of a non-metallicbio-compatible material, such as a ceramic material or a plasticmaterial.

In an alternative embodiment of the invention, a spike may be extendedby protrusions on the balloon that expands the connector. Preferably,the balloon is aligned with the connector so that the protrusions canapply force to the correct portions of the connector.

FIGS. 7U–7V illustrate a bi-stable spike configuration 630, inaccordance with a preferred embodiment of the invention. Configuration630 comprises a parallelogram 632 and a spike 634. In a preferredembodiment of the invention, spike 634 has a non-flat profile, forexample an arc-segment, seen more clearly in FIG. 7V. In a preferredembodiment of the invention, spike 634 has two stable states, a firstone shown in FIG. 7U, in which the profile of the spike keeps itstraight and a second one shown in FIG. 7V, in which the spike bends ata desired location. In a preferred embodiment of the invention, whenparallelogram 632 is distorted (by expansion or by being pressed againstby a balloon), the profile of the spike is flattened, allowing it tobend as shown in FIG. 7V. In a preferred embodiment of the invention,the spike is elastic, super-elastic or shape-memory, and trained to acertain bend. However, the spike is prevented from bending by itsprofile. Alternatively or additionally, the spike is bent plastically,using a balloon or using other methods, for example as described herein.Alternatively or additionally, to a bi-stable configuration, amulti-stable configuration, having three or more stable configurationsmay be used. Additional bi-stable constructions and especially cells forthe cylindrical portion of the connector, which constructions may beuseful for anastomotic connectors in accordance with some preferredembodiments of the invention, are described in PCT publication WO98/32412, the disclosure of which is incorporated herein by reference.

FIG. 7N is a plan view of a connector 410 in which a plurality of spikes412 are extended out of the connector plane when the connector isradially expanded (as indicated by an arrow 418. In connector 410, theparallelograms of previous embodiments of connectors are replaced byellipses 414. Spikes 412 are connected to a lower side of an ellipse.When the ellipse is expanded, the lower side twists and the spikes areextended out of the connector plane. Alternatively, the spikes aresuper-elastic, elastic of shape-memory and twist when a restraint isreleased.

An additional feature shown in FIG. 7N is a tissue block 422 on a spike420. This tissue block stops tissue from advancing too far ontoconnector 420. Alternatively or additionally, the tissue block causesthe spike set on the opposite side of the connector to do the advancingwhen the connector shrinks axially.

Alternatively or additionally, to parallelograms and ellipses, othergeometrical shapes may be used for the distorting elements of theanastomotic connector, for example hexagons, squares, trapezoids,asymmetric four-sided shapes and circles. Additionally, a plurality ofdifferent geometrical shapes may be combined in a single connector.

FIG. 7O illustrates a parallelogram portion 590 of a connector, whichportion includes a ratchet mechanism for preventing collapsing of theconnector, in accordance with a preferred embodiment of the invention.Different types of ratchet mechanisms may be suitable. In the example ofFIG. 7O, the ratchet mechanism includes a belt 592 having a plurality ofbumps 598 formed thereon. These bumps are engaged by an engager 596formed on a mating strip 594. Reference 586 indicates parallelogram 590in an un-expanded condition and reference 588 indicates parallelogram590 in an expanded position. As the parallelogram expands (radially)belt 592 slips through engager 596. As shown by a reference 589, a sideview of belt 592, the bumps may be formed symmetrically (598) orasymmetrically (599). In a preferred embodiment of the invention, theasymmetric bumps preferentially restrict backwards movement.Alternatively, the bumps restrict any type of movement, and assuming theforces at deployment are larger than during the life-time of the device,the connector does not collapse. In a preferred embodiment of theinvention, such a ratchet mechanism provides a self-tighteningcapability to the device. Although a belt with bumps has been described,other ratchet mechanisms may be used, for example, a belt with holes ana single bump on the engager. In this embodiment, the engager may beformed at a vertex of the parallelogram, possibly eliminating a need fora separate mating strip 594.

In a preferred embodiment of the invention, the ratchet mechanism may beutilized in association with a flexibility of the connector, to restrictthe final connector geometry. In one example, the ratchet is connectedaxially, rather than radially. Thus, the radial expansion will set theaxial shortening, however, even if the device radially shrinks, forexample elastically, to a “trained” radius, the axial shortening willremain. Thus, it is possible to axially shorten the connector withoutchanging the designed radius. In an opposite example, the axialshortening may be limited using flexible struts arranged axially in theparallelograms. When the connector is radially expanded, it will shortenaxially, distorting the struts. When the expansion force is removed(e.g., a balloon), the radial expansion will remain, due to atrans-axial ratchet mechanism, but the axial shortening will be at leastpartly undone by forces exerted by the flexible struts. Thus,independent control of axial and radial expansions/contraction may beachieved using suitable axial and trans-axial ratchet mechanisms.

FIGS. 8A–8D illustrate a method of performing an anastomosis inaccordance with a preferred embodiment of the invention. In FIG. 8A, agraft 38 is guided along a guide wire 36 through a hole 118 and out ofthe aorta. A friction ring 120 is attached to a preferably evertedportion 116 of the graft. Preferably, a tapering 114 is provided to easethe exit of the graft from the aorta. A ring 110 with pins 112 is shownpositioned further proximally along guidewire 36. Alternatively, thering with the pins may be on the graft and friction ring 120 be furtheralong guide wire 36. Alternatively or additionally, no friction ring isprovided and pins 112 will engage only graft 38 and preferably foldback. In FIGS. 8A–8C, the graft and the anastomosis connectors arepreferably in a compressed configuration. Alternatively or additionally,the connectors are expanded before inserting attaching ring 110 to ring120.

In FIG. 8B, graft 38 is outside aorta 30 and is preferably pulled backagainst the aorta, for example by pulling back guide wire 36. Ring 110is pushed forward so that pins 112 pierce aorta 30, graft 38 andfriction ring 120. In a preferred embodiment of the invention, ring 120is pushed by inflating a balloon on guide wire 36, just proximal to ring110, so that the inflation of the balloon pushes the ring forward.Alternatively or additionally, a second balloon may be inflated on theother side of ring 120, to urge ring 120 towards ring 110. Alternativelyor additionally, one or both of these pushing forces are applied bypulling wires coupled to graft 38 and rings 110 or 120.

In FIG. 8C, the anastomosis is nearly complete, however, an opening 118is not yet expanded. In FIG. 4D, the opening is expanded and theanastomosis is complete. Opening 118 may be created by making one orboth of rings 110 and 120 of a super elastic, elastic or shape-memorymaterial and by reliving a constraint which maintains them in acompressed configuration. Alternatively or additionally, a balloon maybe inflated in opening 118 to plastically deform the anastomosisconnection. Alternatively or additionally, the same balloon used forurging the rings together may be further inflated, to expand theopening. In a preferred embodiment of the invention, the balloon has twoinflation levels, a first inflation level at which the balloon urges therings towards each other and a second inflation level at which a moredistal portion of the balloon expands radially. Alternatively oradditionally, the balloon is deflated after urging the rings together,advanced into opening 118 and re-inflated to expand the opening.

It should be appreciated that similar methods may be used in conjunctionwith a ring connector which does not use a second ring and in which thespikes are folded back by pushing them against an anvil. A balloon wouldthen preferably perform the function of an anvil. Alternatively oradditionally, the balloon expands an anvil which then collapses when theballoon is deflated.

FIG. 8E illustrates a friction ring in accordance with an alternatepreferred embodiment of the invention. Views 1–3 show the ring in a sideview and in cross-sectional views, when the ring is collapsed. In view4, the ring is unfolded and has a larger diameter. Portions “A” and “B”interleave to form a single ring which is folded such that a top layercomprises of portions “A” and a bottom layer comprises of portions “B”.In a preferred embodiment of the invention, the spikes of ring 110 areinserted into portions B of the ring, in FIG. 8B above.

In a preferred embodiment of the invention, the friction ring mayinclude a plastic or a super-elastic, elastic or shape-memory stiffener,so a stiff ring is required only on one side of the anastomosis.Alternatively or additionally, neither side comprises a stiffener,rather, both are relatively flexible.

FIGS. 8F–8I illustrate different relative placements of the ring(s),aorta 30 and graft 38, in accordance with preferred embodiments of theinvention. In FIG. 8F, ring 110 is in the aortic blood flow. Inaddition, an aortic flap 124 may be left dangling as a result ofcreating the hole in the aorta. In a preferred embodiment of theinvention, such an aortic flap is pushed put with graft 38 and is thentrapped by spikes 112 and/or by the pressure between rings 110 and 120(shown as flap 124′). In a preferred embodiment of the invention, ring120 is wider than everted portion 116 of graft 38. Thus, ring 120 mayform an external seal against aorta 30. Preferably, ring 120 includes adepression to accommodate everted portion 116, so that the outer portionof ring 120 is flush against the aorta. In a preferred embodiment of theinvention, ring 120 includes short spikes to which everted portion 116is attached. Alternatively or additionally, ring 120 includes a ridgefacing ring 110.

In FIG. 8G, everted portion 116 of the graft is inside the aorta. In apreferred embodiment of the invention, silicon ring 120 is not preloadedon everted portion 116, rather ring 110 is so preloaded. To perform theanastomosis, ring 120 is preferably pulled back (or pushed back) ontospikes 114, preferably using a balloon on the outside of graft 38.Alternatively or additionally, the balloon is inflated inside graft 38,to hold ring 120 from inside the graft.

In FIG. 8H, everted portion 116 is also inside the aorta. However, ring110 is now between the aorta and everted portion 116. In a preferredembodiment of the invention, ring 110 includes short spikes 122 whichengage everted portion 110. Alternatively or additionally, ring 110 isglued or otherwise attached to everted portion 116. In a preferredembodiment of the invention, ring 110 includes a sealant material whichseals the gap between everted portion 116 and aorta 30. Alternatively oradditionally, ring 110 includes a coating which induces blood clottingand/or tissue bonding at the connection. In a preferred embodiment ofthe invention, no ring 120 is used. Rather, spikes 114 bend back uponthemselves after they pierce aorta 30, in a manner indicated above.

In a preferred embodiment of the invention, preferably where no ring 120is used, spikes 114 are preferably super-elastic, elastic orshape-memory and have a resting state whereby the spikes are bent at ornear their base. In a preferred embodiment of the invention, spikes 114are maintained at a straight configuration using a thin framework whichfits between everted portion 116 and aorta 30. Once the pins passthrough the aorta, the framework is removed, allowing the pins to foldback and/or to bring together everted portion 116 and aorta 30.

In FIG. 8I everted portion 116 is everted by 180 degrees, so there is nonon-endothelial contact between the anastomosis connector and the blood.In addition, only smooth surfaces are presented to the blood (no raggededge of graft 38), so there is less chance of turbulence. In a preferredembodiment of the invention, after the anastomosis is completed, theconnector is pushed out of the aorta, preferably using a balloon, sothat the entire connector is outside both blood vessels, for example asin FIG. 3G, with the connector outside the protrusion of theanastomosis.

In a preferred embodiment of the invention, the connection between therings is provided by magnetic force, for example as described in“Non-suture micro-vascular anastomosis using Magnet rings: Preliminaryreport”, by Obora Y., Tamaki N. and Matsumoto S., in Sur Neurol (UNITEDSTATES) February 1978, 9 (2) p 117–120, ISSN 0090-3019, the disclosureof which is incorporated herein by reference. In a preferred embodimentof the invention, the rings comprises a magnetic material. Alternativelyor additionally, only rigid parts of the rings are magnetic and aresituated or held within or between non-magnetic, more elastic parts.Alternatively or additionally, only one of the rings is magnetic, withthe other ring preferably being ferromagnetic. Preferably, the magneticportion is extra aortic, so that it does not impede flow. Alternativelyor additionally, a magnetic force may be used to bring the two ringstogether, even if the maintenance of the connection is mechanical. Inone example, indicated above, one ring is magnetic and the other isferromagnetic. In another example, a magnetic force is applied fromoutside the body, for example using a large electromagnet. Alternativelyor additionally, the two rings are magnetized so that they automaticallyalign in a desired relative orientation, for example, so that spikes andholes line up.

In some of the above described embodiments, the ring performs twofunctions, namely aligning the spikes with the tissue to be pierced andmaintaining the anastomosis opening. In addition, the ring exertspressure along its entire circumference, not only where there arethrough spikes. In some anastomosis connections, some of these functionsare not required and/or may be performed without a ring. In one example,if a round opening is cut in the aorta, there is no need to maintain theopening size. In another example, if the spikes are close enoughtogether and/or in other situations, there will be no leakage, even ifthe ring does not apply pressure along the entire circumference of theanastomosis. In a preferred embodiment of the invention, the alignmentfunction is performed by a framework which is removed after theanastomosis is completed. Thus, the completed anastomosis comprises aplurality of spike connectors without a stiffening ring. In a preferredembodiment of the invention, the spikes remain interconnected by aflexible connector, such as a silicone ring. Alternatively oradditionally, the spikes are not interconnected. In a preferredembodiment of the invention, such a framework comprises an anvil againstwhich the spikes are bent. Alternatively or additionally, the frameworkcomprises a ring which is removed from the spikes after the spikes areinserted.

FIGS. 8J–8P illustrate several embodiments of the invention, in whichthe anastomosis device urges the graft radially against the lips of thehole in the aorta.

FIG. 8J is a side cross-sectional view of an anastomotic connector 424which is positioned in a hole in a wall of aorta 30, but is un-expanded.Connector 424 comprises a central section 430, a plurality of upperspikes 428 and a plurality of lower spikes 426. Lips 430 of a graft 38are everted 180° over connector 424. Also shown is an un-inflatedballoon 436 which is positioned inside the connector, for expanding it.

FIG. 8K shows connector 424 after balloon 436 is expanded. As explainedabove, the radial expansion causes axial shortening, which shorteningcauses spikes 426 and spikes 428 to engage aorta 30. Preferably, theseal against blood leakage is by the inward pressure of the aorta, whichpressure acts against the expanded (and preferably relatively rigid)central section 430. Thus, the spikes are only required in order tomaintain the relative positions of the graft and the aorta, not forholding the anastomosis together. In FIG. 8K, a portion 437 of lip 432is shown to be everted by spikes 426, possibly forming an additionalsealing location in the anastomosis. Alternatively, lip 432 is madeshorter so that there is no portion 437 to be everted.

In a preferred embodiment of the invention, the pressure-seal betweenthe aorta and the graft is enhanced, using a bead 434. In a preferredembodiment of the invention, the bead comprises a thickening of theconnector material. Alternatively or additionally, the bead comprises aportion of the connector that rotates out of the connector plane.Alternatively or additionally, the bead comprises an element that foldsout, as described above concerning spikes. In a preferred embodiment ofthe invention, the bead is not continuous, rather, a plurality ofindividual beads are formed around the circumference of the connector.Possibly, a plurality of bands of beads is provided on the connector.Alternatively or additionally, The bead comprises a substantiallycontinuous bead (possibly excepting weakened locations at parallelogramvertices) that circles the connector.

FIGS. 8L and 8M illustrate a connector 438 and a connector 440 whichillustrate different arrangements of spikes. In both of the illustratedconnectors spikes 426 and spike 428 are staggered, possibly reducing thetrauma to the aorta. In connector 438 (FIG. 8L) six spikes 428 and sixspikes 426 are provided. In connector 440 (FIG. 8M) four spikes 428 andfour spikes 426 are provided. In alternative embodiments, differentnumbers of spikes may be provided, possibly different numbers of spikes426 and of spikes 428. Additionally, staggering schemes other than 1/1may be used. One advantage of staggering is that relatively longerspikes may be used. Possibly, an advantage of longer spikes is that theycan pin together the various layers of the aorta and prevent dissectionof the aorta.

Figure designation 8N is intentionally skipped.

FIGS. 8O and 8P illustrate connectors 442 and 448 in which only lowerpins (corresponding to pins 426) are used. Thus, the anastomosisconnection does not require any part of the connector to be in contactwith the blood. In FIG. 8O, lower spikes 444 are preferably folded in,to better grasp the aorta. Alternatively or additionally, a plurality ofhidden spikes 446 may be provided to engage the aorta and prevent axialmovement of the graft. Possibly, spikes 446 also prevent dissection ofthe aorta, especially if they are curved, barbed or not parallel to theaorta wall.

A particular feature of this type of anastomosis is that there iscreated a pocket 452 for blood to enter between the graft and the aorta.This pocket is formed between a topmost end 456 of the graft (which hasa rounded profile) and an edge 454 of the hole in the aorta (which has asquare profile). Blood may enter that pocket and cause dissection of theaorta. Also possibly, the blood will pool and promote clot formation. Ina preferred embodiment of the invention, spikes 446 are provided to urgeend 456 against edge 454, so no blood can enter. Alternatively oradditionally, bead 434 serves this purpose.

In FIG. 8P, connector 448 forms a flared anastomosis, in which theextent of the pocket is reduced and/or the pocket is eliminated, becauseend 456 is urged against edge 454 by the form of the anastomosisconnection.

FIGS. 8Q and 8R illustrate a pull-wire anastomotic device 460, inaccordance with a preferred embodiment of the invention. FIG. 8Q is aperspective schematic view of connector 460 showing a base ring 462 anda plurality of spikes 464 that pass through the ring. The cross-sectionof the spikes may be circular. Alternatively, the cross-section may berectangular, may be an arc-portion or have other geometry's.Alternatively or additionally, the cross-section of the spike may varyalong the length of the spike.

FIG. 8R is a side cross-sectional view of connector 460. When performingthe anastomosis, the spikes 464 (all together or possibly temporallystaggered) are pulled in the direction indicated by an arrow 466,relative to base ring 462. A barb 468 at the end of the spike engagesthe aorta. Graft 38 is preferably everted over the spike, so that whenthe base-ring is brought towards the aorta, the everted portion of thegraft abuts the aorta. Possibly, the eversion is a 90° eversion.Alternatively, the eversion is a 180°, as indicated for example by areference number 469. In some embodiments, ring 462 remains outside theaorta. In other embodiments, part or all of ring 462 is brought into thehole in the aorta. Possibly, ring 462 includes a rim 463, which limitsthe advance of the ring into the aorta.

In a preferred embodiment of the invention, barbs 468 do not extendbeyond base-ring 462, during the insertion of the anastomosis device. Inone embodiment of the invention, a spike 464 is bent inwards, asindicated by a dashed profile 470, so that barb 468 is within themaximum radius of ring 462. In a preferred embodiment of the invention,spike 464 is pre-bent. However, a rigid tunnel 471 in base-ring 462forces the spike portion which passes through the base-ring to beperpendicular (or at any other desired angle) to the base ring. Thus,when the bent portion 470 of the spike is brought into tunnel 471, barb468 is extended outwards. Alternatively, the spike may comprise elastic,shape memory or super-elastic materials, as described above. In anotherembodiment of the invention, spike 464 is rotated 90°, duringdeployment, as indicated by an arrow 472, so that the barb moves fromthe plane of the connector to extend outside the connector.

Alternatively or additionally to barbs 468 moving out of the connectorplane during the deployment of connector 460, base-ring 462 comprises anexpandable base ring, which has a smaller radius while it is beinginserted.

In a preferred embodiment of the invention, connector 460 includes aone-way block 474 which prevents the removal of base-ring 462, after theanastomosis is performed. Alternatively, the removal is prevented by akink in the spike, for example one caused by bend 470. Alternatively oradditionally, the removal is prevented by a bending or flattening of thespikes. In a preferred embodiment of the invention, the spikes areformed of a single material having same mechanical properties alongtheir entire length. Alternatively, especially for the embodiment usingbend 470, a spike may comprises a first, flexible, portion and a second,more rigid, portion. Possibly, the flexible portion comprises a thread.In a preferred embodiment of the invention, an extending (waste) part ofthe spike is cut-off by an insertion device, possibly while flatteningthe spike to prevent the cut end from retracting through hole 471.

Alternatively or additionally, the spikes are self-shortening. In oneembodiment of the invention a self-shortening spike is formed by atwo-layer material in which one is elastic, super elastic or shapememory and is stretched (or shrunk) by a certain amount. When arestraint is removed (or the or shape-memory is activated), the spiketwists in a spiral, shortening by a much more than the certain amount.Possibly, a plurality of weakenings are provided along the spike toassure spiral collapsing. Such an axially shortening may also be forother parts of the connector, for example, for causing axial shorteningof the connector. Possibly, the spikes twist over substantially theirentire length, thereby being screwed into the blood vessel tissue.

FIGS. 8S–8X illustrate a mechanism for folding spikes in which a radialexpansion is substantially decoupled from axial length changes, inaccordance with a preferred embodiment of the invention. FIGS. 8S and 8Tillustrate part of a ring segment of an anastomotic device 700. In acomplete device, the right end of the part shown is attached to the leftend, forming a ring which is perpendicular to the plane of the paper.Device 700 is formed of a plurality of cells 702, having a spike 704extending perpendicular to the segment and/or a spike 706 extending inthe opposite direction. Thus, device 700 has a similar form as device 60of FIG. 4A. As shown in FIG. 8T, when the device is radially expanded(shown here as a lengthening of the segment) spikes 704 and spikes 706are folded towards the ring segment. Preferably, the movement of thespikes is on a plane which is tangent to the surface of the device 700.However, by a suitable weakening of a joint 710 which connects spike 704to cell 702, motion in other planes can be achieved. It should be notedthat also motion in the tangent plane enables the spikes to engagetissue that is outside the anastomotic connector.

Although only a single ring with spikes on two sides thereof is shown, adevice having a plurality of segments may also be constructed inaccordance with a preferred embodiment of the invention. It should benoted that a characteristic of some embodiments of device 700 is thatthere is substantially no axial shortening coupled with the radialexpansion. Thus, in a device with several types of ring segments,various types of relationships between axial and radial expansion, suchas shown in FIG. 5, can be achieved.

FIG. 8U shows a device 710 having features similar to those of device700. A cell 712 replaces cell 702. In addition, two types of spikes areshown, a straight spike 716 and a round spike 714. FIGS. 8V, 8W and 8Xshow the effect of radial expansion on a spike 714. In FIGS. 8W and 8Xtwo spikes are shown, to show the relative positions of two opposingspikes, as may be used in some embodiments of the invention. As theradial expansion proceeds, spike 714 advances in a scythe like motion,hooking and then engaging the tissue into which the spike enters. Itshould be noted that an anastomosis device 700 or 710 can be made verynarrow, for example substantially the same as a thickness of the “side”vessel”, so that there is a minimal protrusion.

FIGS. 8XA–8XH illustrate a mechanism for axial retraction and/orextension of spikes, in accordance with a preferred embodiment of theinvention.

FIG. 8XA illustrates an anastomotic device 720, in a plan view. Aplurality of spike cells 722 are attached to a body 721. Each spike cellpreferably comprises one or more spikes 724, one or more rings 726and/or one or more anchors 728. Springs 726, as shown, are in a relaxedstate. In alternative embodiments, the springs are “normally extended”,rather than “normally retract” as shown.

In a typical use, a graft is everted or otherwise transfixed by spikes724. A plurality of tissue stops 730 are preferably provided to limitthe advance of the graft on the spikes. Spikes 724 are then advanced,preferably by applying an advancing force onto anchors 728. Thisadvancing step can be performed inside the body or outside of it. Insome embodiments, advancing the spikes causes them to pierce and/ortransfix a vessel to which the graft is to be connected. In otherembodiments, shown below, the advancing causes the spikes to advanceinto a hole in said vessel. When the anchor is released, spikes 724retract. In some embodiments, the retraction engages the “side” vessel.Alternatively or additionally, the retraction seals the anastomosis. Ina preferred embodiment of the invention, each spikes retracts anindividual amount, thereby matching irregularities in the anastomosis orin the two blood vessels.

FIG. 8XB illustrates a variant device 740 in which a spike 744 isrestricted from movement perpendicular to the device surface by one ormore bands 742. This restriction is useful, for example, if spikes 744are pre-bent. However, as long as a spike 744 is retracted, bands 742will maintain in the plane of its spike cell. In use, the spike's tip ispressed against the side vessel and then the spike is advanced, piercingand/or transfixing the side vessel before the spikes bend.

Generally, the retraction of the spikes is not complete, for example dueto the transfixed tissue opposing the retraction of spring 726.Alternatively or additionally, the relaxed states of the spring does notfully retract the spikes. Alternatively or additionally, the spikesinclude a protrusion 746 wheich resists the complete retraction thereof.Alternatively or additionally, once the spikes are bent, they resist acomplete retraction.

In a preferred embodiment of the invention, the anastomosis connectorcan be removed by completely retracting the spikes so that theydisengage from the tissue. Preferably, bands 742 straighten the spikes744 so that they do not damage the blood vessels during the removal.

FIG. 8XC shows a variant device 750 having a plurality of spike cells758, in which the extension of a spike 754 has a plastic deformingeffect on a spring-like element 756. An anchor 752 (shown here as a holewhich can be engaged by a suitable protrusion on a deployment device)can be engaged and pulled along the tracks defined by cell 758, toretract the spike.

FIG. 8XD shows device 720 in a side cross-sectional viewed while beingdeployed in a side-to end anastomosis. As shown, spikes 724 are extendedand bent. In a preferred embodiment of the invention, spikes 724 areinserted into the body bent. Alternatively or additionally, the spikesare manufactured or treated to be bent and are maintained in a straightconfiguration using a restrainer or using bands 742 (not shown). Whenadvanced or when the restrainer is retracted, the spikes bendelastically or super-elastically. Alternatively or additionally, thespikes may be formed of a temperature-triggered shape-memory alloy.Alternatively or additionally, bands 742 are arranged to bend spikes 724and/or point them at an angle to the axis of the device, as they areextended. Alternatively or additionally, the spikes are bent by an innermandrel (not shown), for example an inflatable balloon.

In FIG. 8XE, anchor 728 is released (or retracted), so that the spikesare shortened. Retracting the anchor or releasing it preferably use anouter or an inner tube-tool (not shown) which engage the anchor. Theexact form of the tube-tool depends on the anchor used. In the exampleof protrusions 728, which extend out of the surface of device 720, asimple tube which fits over the connector can be used.

It should be noted that each spike is independent. Thus, in a preferredembodiment of the invention, the retraction and/or release of theanchors may be for individual anchors or for sub-groups of the entireset of anchors.

Alternatively or additionally, to retraction and advancement using anexternal tool, the motion of a spike may be controlled by the deviceitself. In one example, anchor 728 is coupled, for example by a wire, toa vertex of a parallelogram which forms a part of the body of device720. When the device expands radially, the vertex retreats from theedges of the device, pulling the spike back with it (preferably alongthe tracks defined by cell 722). In another example, as a parallelogramvertex retracts, it twists out of the surface of device 720, releasinganchor 728.

FIGS. 8XF–8XH illustrate a dual action mechanism 760 for a single spike762, in which a single spike moves both advances and retracts. In anelastic example, spike 762 is connected in series to a normally expandedspring 766 and to a normally retracted spring 764. When an anchor 768associated with spring 766 is released, spike 762 advances, as shown inFIG. 8XG. When an anchor 770 associated with spring 764 is released,spring 764 retracts, retracting spike 762, as shown in FIG. 8XH. Thestarting and ending retraction length need not be the same.Alternatively or additionally, one or both of the “springs” can beplastic deformations element deformed by moving the suitable anchors.Alternatively or additionally, the springs can be in other orders thanshown and/or can have different lengths.

In a preferred embodiment of the invention, the release of the anchorsis by a suitable deployment tool. Alternatively or additionally, theanchors are self-triggered. FIG. 8XG illustrates an optionalself-trigger 772, which maintains spring 764 in an extended state, usinga protrusion 774 on the spring. When anchor 768 advances far enough itpushes against a protrusion 776 of the self-trigger, causing theself-trigger to bend and release spring 764. The release causes spring764 to constrict and retract the spike. Self trigger 772 may be in thesame plane as cell 760 or above or below it. In some devices, theself-trigger may be plastically deformed or cut but the motion of spike762. In a preferred embodiment of the invention, the two springs are intwo layers, so that when spring 764 retracts is causes a deformation(preferably a bending) of spike 762.

It should be noted that such axial motion and/or double action motionmay also be utilized for anastomotic devices which form their own holesin the blood vessel. Preferably, the spikes are bi-stable or arerestrained in the shape of a tip, so that once they advance, therestraint/bi-stable shape is released and when the tips are retractedthe bend outwards to engage the blood vessel and complete theanastomosis.

In some preferred embodiments of the invention, the devices of FIGS.8XA–8XH include radial expansion capabilities, which may or may not becoupled to the extension of the spikes, as described. In otherembodiments, no radial expansion is provided.

Each of cells 722 may be axially rigid. Alternatively or additionally,especially if the cells are interconnected at both ends, a radialexpansion of the device may cause an axial shortening of the cells. Forexample, if each cell wall comprises a flattened parallelogram, insteadof a single piece and/or by providing suitable weakenings thereon.

As described above, the cells are used for extension and retraction ofthe spikes. Alternatively or additionally, such cells may be used forcontrolling the axial length of the device. In one such example, thedevice comprises two rings, which rings are interconnected by selflengthening and/or self-shortening cells. In another such example,releasable springs are used to cause axial shortening of the device,rather than by releasing a restraint around the entire device. In someembodiments, the force of a single released spring can be used totrigger the release of other springs in addition to or instead ofdirectly deforming the anastomotic connector.

Alternatively or additionally, to the cells being axially arranged, thecells may be arranged in a trans-axial and/or a diagonal direction(relative to the main axis). Thus, the spike scan be extended and/orretracted in various directions. Also, both the axial length and thecircumference may be controlled using suitably arranged cells.

It should be appreciated, that as in other embodiments of the invention,there is a wire range of control techniques which may be practiced. Inparticular, various allocations of control mechanisms between the deviceand the deployment tool can be achieved.

FIG. 9A illustrates a sleeve attachment 130 for a graft 38, inaccordance with yet another preferred embodiment of the invention. Inmany cases, everting graft 38 may damage the graft. In a preferredembodiment of the invention, a sleeve attachment 130 is everted over aring 110 and then attached to graft 38. Alternatively or additionally,the sleeve is first attached to the graft and then everted over theconnector. In a preferred embodiment of the invention, sleeve 130comprises a blood vessel segment that has a larger inner-diameter thangraft 38. In a preferred embodiment of the invention, sleeve attachment130 is glued to graft 38. Alternatively or additionally, the attachmentis sutured to graft 38. Alternatively or additionally, it is weldedand/or attached using a plastic flowable material.

FIG. 9B illustrates attaching a patch 134 to the outside of a bloodvessel 132, using devices and/or techniques as described herein.Although a flat patch 134 is shown, patch 134 may comprises a graft withan end tied off. Preferably, the patch is pushed out of vessel 132,through a hole 133. A connector 136 pulls the patch against vessel 132.Alternatively or additionally, a spike type connector 137 may be used tomaintain the patch in contact with the vessel. A connector such as aconnector 137 does not maintain hole 133 in an open configuration, sothere is usually less strain on vessel 132. In many cases, there will beno leakage through hole 133, even if the patch is not hermeticallysealed, due to the elasticity of the walls of vessel 132.

Patching a blood vessel may be desirable if the vessel wall is damagedat that point, to relive strain, for example caused by an anastomosisand/or to support an electrode or a different wire or tube which exitsthe blood vessel. In a preferred embodiment of the invention, such apatch is applied for a side-to-side anastomosis, either on the outsideof vessel 132 or on its inside. Preferably, a single connector is usedboth for the anastomosis and for the patching.

FIG. 9C illustrates configurations in which patch 134 is inside theblood vessel. In a configuration 138, the connector is situated alongthe edge of the patch, possibly covering any ragged edges and engagesvessel 132. Preferably, the engagement is by pins which pass through thevessel. Alternatively or additionally, connector 138 passes through ahole in vessel 132, as shown for example in FIG. 9B. In configuration140, a spike pierces both patch 134 and vessel 132. The spike may bendback. Alternatively or additionally, a friction material, such as a ringis provided on the other side of vessel 132, preferably after beingpushed out through a hole in vessel 132. In configuration 141, a spikeis embedded in- or otherwise attached to-patch 134, so that there is nocontact between the connector and the blood flow.

A PCT application titled “Vascular Port Device”, filed in the Israelreceiving office on even date as the instant application, with sameapplicants, the disclosure of which is incorporated herein by reference,describes various types of seals for holes in blood vessels. Inparticular, some of these seals may be applied over an existing catheterto seal an existing hole.

Alternatively or additionally, some of these seals are actuallyanastomotic devices, which, when they fail, can self-seal. One type ofsealing mechanism described is that spikes, which engage the bloodvessel around the rim of the hole in the blood vessel, move towards eachother, thereby causing the rim portions to abut and seal the hole. Thepresent application describes various mechanisms that can be used tocontrol the expansion and/or collapsing of an anastomotic connector,such that the spikes move towards each other and seal the hole of theanastomosis.

FIG. 9D illustrates a strain reliving device 142, attached to vessel132, either on its inside or on its outside. In a preferred embodimentof the invention, device 142, shown as a grid, is covered with a graftmaterial. Dots 144 indicate pins that engage vessel 132 itself. In apreferred embodiment of the invention, the pins are super-elastic,elastic or shape-memory and are maintained in a configuration where theyare pointing away from the vessel wall. When device 142 is positioned ina desired location, a restraint is released and the pins bend to engagethe vessel wall. The pins may be distributed evenly over device 142.Alternatively or additionally, the distribution is uneven, preferably tomatch a strain pattern.

In a preferred embodiment of the invention, device 142 is used to relivestrain on a wall of vessel 132. The distribution of pins 144 willusually affect the amount and directionality of the strain in vessel132. Although device 142 is shown as being substantially planar, in apreferred embodiment of the invention, device 142 may be curved or evencylindrical, to match the shape of the vessel.

In a preferred embodiment of the invention, device 142 provides aframework for an endoscopic procedure or for a catheter based procedure,and as such, it may be inserted outside of the blood stream. In apreferred embodiment of the invention, device 142 is attached to a heartor to an aorta, preferably for aid in performing a bypass procedure.Preferably, the framework is provided through an endoscope. Preferablythe framework remains loosely coupled to the endoscope, for example viaa cable for providing power (such as air pressure) or via a safety line.

Device 142 may include rails or other guidance mechanisms for guidingthe procedure,

-   -   such that tools and/or endoscopes or other tubes may travel        along the guide rails. Such rails preferably follow the surface        of device 142. In a preferred embodiment of the invention, the        rails include junction points or otherwise identifiable points        where a guided tool may fix its position relative to the device.

In a preferred embodiment of the invention, device 142 may be controlledto be at a selected one of two or more configurations, for example, byinflating a balloon therein.

Preferably, when the device changes configuration, it changes therelative positioning of body tissues and/or tools which are attached todifferent parts of the device. When the procedure is completed, thedevice may be removed by folding it. Preferably, the device is removedusing the same endoscope/catheter used to insert it. Alternatively oradditionally, it may be removed via a keyhole or other surgical wound orusing a different catheter. Preferably, all the pins are bent in such adirection that folding the device retracts them from the tissue. In apreferred embodiment of the invention, the device is folded by engagingit with one or more arms comprising a super-elastic, elastic orshape-memory material and relieving a restraint on the arms so that theyfold, folding the device with them. Alternatively or additionally, theholding strength of the pins may be reduced if they comprise ashape-memory material that is cooled below its critical point.Alternatively or additionally, the framework is maintained in anexpanded configuration using an inflatable device, such as a balloon.When the balloon is deflated, the device preferably collapses as aresult of its own elasticity.

Many variations on the above-described devices may be practice withinthe scope of some preferred embodiments of the present invention. In apreferred embodiment of the invention, the connector is smooth, at leastin portions thereof that are in contact with blood flow, to enhancebio-compatibility. Alternatively or additionally, the connector is roughor has grooves defined therein, at least in portions thereof which arein contact with blood vessel tissue, to enhance attachment to the bloodvessel.

In a preferred embodiment of the invention, the spikes are sharp tobetter pierce the blood vessels. Alternatively or additionally, thespikes are blunt, for example to promote tearing rather than cutting. Ina preferred embodiment of the invention, the spikes have a flatrectangular cross-section, for example for ease of manufacturing.Alternatively or additionally, the spikes have a triangular or acircular cross-section, for example, for better mechanical stability. Ina preferred embodiment of the invention, not all the spikes have thesame cross section and/or sharpness and/or tip shape, for example toprovide a range of mechanical and/or adhesion characteristics.

In a preferred embodiment of the invention, spikes are placed closetogether, so that they can support the anastomosis. Alternatively oradditionally, the spikes are relatively few and/or far apart and theanastomosis is supported by rings to which the spikes are connected andwhich exert pressure on the anastomosis. In a preferred embodiment ofthe invention, the spikes and/or the rings are arranged in two or moreconcentric layers and/or have different bending locations, for example,so that a double seal/anastomosis is formed.

It should be appreciated that a single anastomosis connector may includefeatures from different ones of the connectors described above, forexample, a connector may include both spikes which hold together thevessel and the graft and a structure which urges the vessel and thegraft together.

Much of the above description has centered on the anastomosis connectionat the aortic side of a bypass, however, these anastomosis connectionsmay also be applied to the coronary side of the bypass. It should benoted that once the end of graft 38 and the connector attached theretoare inserted into coronary vessel 22, the situation is the same as whengraft 38 is inside the aorta, i.e., the graft may be pulled out.However, it should be noted that vessel 22 has a smaller diameter, so alower profile connector may be desirable. In addition, it may not bedesirable to push a large connector out of the aorta to vessel 22. Thus,a smaller connector is preferably used for the arterial end of thegraft. Alternatively or additionally, the connector used for vessel 22may combine the functions of tip 37 and of at least part of theanastomosis process.

In a preferred embodiment of the invention, a failed anastomosis may beremoved, either during the attachment process or after it is completed.In one example, if the anastomosis at vessel 22 fails, the tip of graft38 may be cut off and a new anastomosis connector provided along guidewire 36, for connecting at a new point. In some cases, the hole invessel 22 will not leak without any further treatment. Alternatively oradditionally, the hole is patched, either as described above or usingtechniques known in the art, for example, coating it with a flowablematerial. Alternatively or additionally, when the graft is cut, the endof the graft near vessel 22 is sealed off.

FIGS. 10A–10D illustrate an end-to end anastomosis in accordance with apreferred embodiment of the invention. When provided, an anastomosisconnector 152 has a diameter smaller than that of a vessel 150. Aballoon 156 is inflated under one end of connector 152, so that itexpands radially and spikes thereon engage the walls of vessel 150. Asecond vessel 154 is then brought to a position where it overlaps thesecond end of connector 152. When the second end of connector 152 isinflated, it expands radially and preferably also contracts axial.

Thus, a better contact is formed between the two blood vessels.

In a preferred embodiment of the invention, connector 152 includes aridge 153, preferably around most or all the circumference of connector152. Thus, when the two blood vessels are brought together, the ridgeguides an automatic eversion of the two blood vessels.

In a preferred embodiment of the invention, the ridge is not continuousand contains holes and/or gaps, so that the two blood vessel surfacescan be in contact through the ridge.

In a preferred embodiment of the invention, connector 152 is used for anexternally meditated anastomosis. Preferably, connector 152 is formed ofa super elastic, elastic or shape-memory material and is constrained tobe radially compressed by a device which circles connector 152 at ridge153. After the two blood vessels are placed on the connector, therestraint is removed and the two blood vessels are automatically engagedby connector 152, advanced towards each other and attached to eachother. Possibly, they are also everted over ridge 153.

In a preferred embodiment of the invention, when a graft is implantedand found to be too long, it may be sectioned and the sectioned portionsbe attached using an end-to-end anastomosis, as described above.Alternatively or additionally, the graft is attached to supportingtissue so that it does not move around.

FIGS. 10E–10K illustrate an end-to-end anastomosis between a firstvessel 680 and a second vessel 682, in accordance with an alternativepreferred embodiment of the invention.

As a preliminary step, shown in FIG. 10E, second vessel 682 ispreferably threaded using a guide wire 684 and then a roughened balloon686 is inflated in its lumen to grasp vessel 682. Blood flow from vessel688 may be blocked by a blocking catheter 688, through which thefollowing process may be performed. Alternatively or additionally, thecatheter may be used to severe the ends of one or both vessels and tolocate or assist in locating the ends in the body.

In FIG. 10F, a connector 690 is provided. In a cross-sectional view,connector 690 may have a “Y” profile. Preferably, connector 690 includesa first set of spikes 691 for engaging vessel 680 and a second set ofspikes 693 for engaging vessel 682. The two sets of spikes arepreferably connected to a body 695 that has a base 697. If connector 690is deployed using plastic techniques, a balloon 692 may be provided.Alternatively or additionally, if connector 690 is deployed usingelastic, super-elastic or shape-memory techniques, a restraining element694 may be provided.

In FIG. 10G, connector 690 is flattened, so that its profile isperpendicular to the two blood vessels. Possibly, a portion 696 of theconnector remains axial. Several methods as described herein may be usedto flatten connector 690. In one embodiment, connector 690 iselastically striving to resume a flattened configuration, oncerestraining element 694 is removed. In another embodiment, the base ofconnector 690 is restrained from expanding by its geometry. Thus, when aballoon 692 is inflated inside of it, the rest of the connector followthe counter of the balloon. Possibly, an orientation as indicated byreference 698 is achieved, rather than a perpendicular orientation.Possibly, the rotation and/or further rotation of connector 690 isperformed after the two vessel are brought against the connector and/orafter the two vessel are engaged by the spikes.

In FIG. 10H, vessel 682 is brought towards connector 690, for example byretracting guide wire 684. The severed end of vessel 682 is thuspartially everted over connector 690. Possibly, folding into the lumenof vessel 682 is prevented by balloon 682, balloon 692 and/or an axialportion 696.

In FIG. 10I, spikes 693 bend and engage vessel 682. Several methods maybe used to bend these spikes. In one example, expansion of connector 690will cause the spikes to bend, possibly, without appreciable bending ofthe other spikes, by each set of spikes being connected to differentlyshaped parallelograms, which respond differently to different amounts ofradial expansion. In another example, the spikes are elastic,super-elastic or shape-memory and bend when a restraint is released,again, possibly by the expansion of connector 690. Alternatively oradditionally, spikes 693 and spikes 691 bend together, at a later time,for example as a result of further expansion of connector 690.

In FIG. 10J, vessel 680 is advanced and everted. In FIG. 10K, spikes 691are bent, completing the anastomosis. Preferably, expanding connector690 radially enhances the grasping of spikes 691 and 693. Preferably aplurality of tissue blocks are formed on these spikes, so that when thespikes bend more, they urge the vessels against each other.

FIG. 10L illustrates a side-to-side anastomosis, utilizing a connectorsimilar to that used in the embodiments of FIGS. 10E–10K. In this typeof connection, the connector is first rotated to be perpendicular to theflow between the vessel (opposite the rotation in FIG. 10G and then thevessels are urged together. Possibly, the connector is advanced endfirst and then rotated.

In this embodiment, however, the spikes are inside the blood flow, sothey can also be bent using suitable balloons.

FIG. 10M shows a front view of an anastomosis device 690 suitable foruse in FIGS. 10E–10L. In the embodiment shown, connector 690 comprises abase-ring 697, which may, for example be plastically deformable. Thefigure shows the resting state of the device, i.e., when a restraint isremoved, the device will achieve the shape shown. However, when the ringis expanded, for example using a balloon, spikes 691 and 693 will bebent, preferably suing one of the many mechanism described herein.

In a variation of a standard anastomotic procedure, two severed parts ofa blood vessel may be reattached by first attaching a “half” anastomoticconnector to each severed end and then attaching the two “halves”connectors, for example using a graft which bridges the two connectorsor by mechanically attaching the two device halves. A half connector maybe, for example half of the connector shown in FIG. 10A. A use of such aprocedure is trauma surgery, such as for connecting severed limbs orwhen implanting certain organs, where many end-to-end anastomosisconnections are to be performed. Preferably, each pair of “half”connectors is marked to allow easy identification of the matching ends.Alternatively or additionally, each pair of “halves” is connected by awire. Thus, the task of identifying the severed vessels and determiningwhether the remaining vessel lengths are sufficient can be separatedfrom the actual anastomosis connection activity and without previouslyperformed connections interfering with the work.

FIG. 11 illustrates a graft delivery system 201, in accordance with apreferred embodiment of the invention. Referring back to FIGS. 2A–L, a“J” shaped catheter 34 includes a lumen through which a guide wire 36may be provided. The lumen may also be used to perform suction, forcollecting debris, to provide other tools, to inject contrast media,drip anti-clotting drugs, to provide saline solution and/or to seal offthe work area from the blood flow. Guide wire 36 has a sharp tip 37which is preferably tapered and which may be used to pierce both aorta30 and vessel 22. Alternatively or additionally, the guide wires areswitched so that different guide wires are used for the differentvessels.

A graft 38 is preferably preloaded with anastomosis connectors 202(aortic) and 204 (coronary), prior to being inserted into the body.Connector 204 preferably includes a tapering surface 206 to ease itsinsertion into the holes created by tip 37. Alternatively oradditionally, a tapering surface 206 may be independently provided overguidewire 36 and retracted when not needed. Preferably, tapering surface206 is an inflatable tapering and/or otherwise expandable surface.

In FIG. 11, a narrower connector profile is used for connector 204 thanfor connector 202. However, this is not a requirement of all thepreferred embodiments of the present invention. A balloon 200 ispreferably provided over guide wire 36 to expand the connectors. Asecond balloon 206 may also be provided. The second balloon may have anarrower cross-section than balloon 206. Alternatively or additionally,balloon 206 may be used in conjunction with balloon 200, to squeeze ananastomosis connector.

In a preferred embodiment of the invention, catheter 34 is not used andgraft 38 is exposed to the blood. Some or all of the elements shown inFIG. 11 are preferably disposable. Alternatively or additionally, atleast some of the elements are sterilizable, for example, guide-wire 36.

FIGS. 12A–12E illustrate an applicator kit 480 (not marked on thefigures) for an anastomosis connector, in accordance with a preferredembodiment of the invention useful for key-hole surgery. In a preferredembodiment of the invention, kit 480 comprises a holder 509 (FIG. 12B,12C), which can selectably hold an aortic puncture sub-assembly 500(FIG. 12A) or a graft insertion sub-assembly 482 (FIG. 12D). A close upof the tip of the holder, including the graft insertion sub-assembly andan inserted graft, is shown in FIG. 12E.

Referring to FIG. 12A, puncture sub-assembly 500 is preferably designedto reduce the danger of puncturing both sides of the aorta. In apreferred embodiment of the invention, a hole-making pin 515 isprotected by a protective sleeve 513. When the tip of hole-making pin515 is pushed into the side of an aorta, protective sleeve 513 retracts(against a spring 523) and exposes the sharp tip of hole-making pin 515,which tip penetrates the aorta. Once the aorta is penetrated, protectivesleeve 513 can slide back forward and protect the other side of theaorta from hole-making pin 515. Spring 523, protective sleeve 513 andhole-making pin 515 are preferably coupled through a cap which compriseselements 514 (body) and 511 (top seal).

Referring to FIG. 12B, aortic punch sub-assembly 500 is shown insertedin holder 509. Attention is directed to an extension 498 of an innersleeve 507 of holder 509. When the hole is punched in the aorta, thisextension also enters the aorta. However, further advance of the holderis blocked by a step-type increase in radius of holder 509.

Once the aorta is pierced, aortic punch sub-assembly 500 can be removed.In a preferred embodiment of the invention, holder 509 includes a seal532, for example a silicon gasket or a tri-leaflet valve made of aflexible and resilient material. Thus, when sub-assembly 500 is removedblood is stopped from exiting the aorta, by the seal. In some cases,some blood will pass by the seal and fill holder 509, above the seal. Ina preferred embodiment of the invention, a pressure relief exit (orvalve) 530 is provided, for blood to exit the holder when new tools areinserted into the holder.

Referring to FIG. 12D, graft insertion sub-assembly 482, comprises aplunger 526 on which a graft (not shown) is mounted. In a preferredembodiment of the invention, a connector graft is mounted on the graftin the following manner. A connector is held inside a restrainingelement 508, so that one set of spikes is extended. A graft is loadedeither on or inside plunger 526 and plunger 526 is inserted through abody 505 and restraining element 508 which is attached at the end of thebody. Then, the graft is everted, possibly manually, over the extendedspikes.

Preferably, plunger 526 is held by a pin 516 so it does not moverelative to a block 504, which is fixed to body 505. When plunger 526and body 505 are inserted into holder 509, pin 516 is released using amechanism including a pin 517, when pin 517 contacts a holder block 503of the holder. The release of the pin allows plunger 526 to advance(relative to restraining element 508) until the anastomotic connector isproperly positioned relative to the holder tip (and thus the aorta). Itshould be noted that the device does not expand at this point, since itis constrained by inner-sleeve 507.

Referring to FIG. 12E, an everted graft 36 is shown with a mountedanastomotic connector 496. When plunger 526 is advanced, the extendedspikes of connector 496 are preferably folded back by a tapering 534formed in inner sleeve 507.

Referring back to FIG. 12C, a pin-type mechanism (518, 519, 520, 521 and522) preferably maintains holder block 503 fixed relative to holder 509.Inner sleeve 507 is preferably coupled to holder block 503. When thepin-mechanism is released, a spring 524 preferably retracts holder block503, thereby retracting inner sleeve 507 and extension 498. As extension498 is the only thing retaining connector 496 from expanding, theconnector expands and performs the anastomosis.

FIG. 12F illustrates an exemplary anastomotic connector 496, in acollapsed configuration 538 and in an expanded configuration 540. Thisconnector is similar to the connector of FIG. 8J, except that the spikesare bent in arcs, rather than in straight angles. Such a modificationmay also be applied to other connector embodiments described herein. Inaddition, depending on the location where the spike exits the graft, aportion of the graft may protrude into the aorta. In some cases, thisprotrusion may aid in sealing pocket 454 (FIG. 80). Additionally oralternatively, the engagement of the aorta by the spikes may cause aradial compression of the wall of the aorta.

It should be noted that in the embodiments of FIG. 12G, as well as inother embodiments, such as those of FIGS. 8O and 8P, it is not necessaryfor the graft to be everted 180°. Rather, an eversion of 90° may besufficient. Further, since the graft is pressed against the “side”vessel, the eversion may be completely dispensed with. However, smallspikes (or other protrusions) are preferably provided inside theanastomosis connector to engage the graft and prevent it from slippingoff the anastomotic connector, during the deployment process.

FIG. 12G illustrates an alternative connector, similar to connector 496of FIG. 12F, but in which one set of spikes is curved and one is bent atsubstantially right angles.

FIGS. 12H–12J illustrate a graft everter 636, in accordance with apreferred embodiment of the invention. Everter 636 preferably comprisesan outer body 638, an inner body 640 and expandable arms 642. A graft 38is preferably extended from a graft delivery sub-assembly 482, with aconnector 496 already loaded in restraining element 508. Graft 38 ispreferably engaged by roughened (possibly by sand-blasting) or barbedends of arms 642. Thus, when plunger 640 is advanced, the arms extendedradially, expanding the graft radius (FIG. 121). The entire everter 636is then advanced towards sub-assembly 482, so that the graft everts andis engaged by extended spikes 644 of connector 496. The spikes mayextend radially or may extend axially, in either case they preferablytransfix the graft in the everted configuration. Thereafter, arms 642are released, for example by axial rotation, to present a smooth side tothe graft, and the graft finishes the eversion over the connector. Insome embodiments of the invention, everter 636 is coupled to the vesselholed. In other embodiments, the tool tools are separate.

In some cases, an oblique connection is desired. In these cases, theeversion may be oblique as well. In a preferred embodiment of theinvention, an oblique eversion is achieved using an oblique anastomoticconnector. Alternatively or additionally, the oblique eversion isachieved by the tip of the vessel holder being non-perpendicular to themain axis of the vessel holder. Alternatively or additionally, theeverter provides asymmetric expansion and/or asymmetric advancing.

FIGS. 12K–12M illustrate an alternative hole-punching sub-assembly 648,in accordance with a preferred embodiment of the invention. Unlikesub-assembly 500, sub-assembly 648 punches a hole, removing a portion ofthe aorta in the process, rather than just forming a hole.

In a preferred embodiment of the invention, the difference betweensub-assembly 648 and sub-assembly 500 is in the provision of an indent651 in a hole-punching element 650 of sub-assembly 648. FIG. 12K shows atip of assembly 648, with punching element 650 extended and FIG. 12Lshows the tip with element 650 retracted. FIG. 12M, correspondsgenerally to FIGS. 12A and 12B and illustrates sub-assembly 648 as awhole and as inserted in holder 509.

FIGS. 12N–12R illustrate two methods of punching a preferably leak-lesshole from outside or inside a blood vessel, in accordance with apreferred embodiment of the invention. Although the reference numbersare copied from FIGS. 12A–12M, the methods of both sets of figures mayalso be practiced in a transvascular approach, especially with regard topunching a hole in the coronary vessel in an aorta-coronary bypassprocedure.

In FIGS. 12N–12P, a hole punching element 650 is forced into aorta 30(FIG. 12N).

Then, element 650 is retracted against protective sleeve 513, cuttingoff a piece of the aorta within indent 651 (FIG. 120). Protective sleeve513 and extension 498 are then advanced into the punched hole, untilprotective sleeve 507 abuts against aorta 30 (FIG. 12P).

In FIGS. 12Q–12R, an outer sleeve 654 is advanced such that onlypunching element 650 is forward of it, then the holder 509 is pushedagainst aorta 30, causing element 650 to enter it (FIG. 12Q). In FIG.12R, protective sleeve 513 is advanced over punching element 650 toremove a part of the aorta. Simultaneously, or afterwards, element 650may be retracted. In an alternative embodiment, sleeve 507 is fused withprotective sleeve 513 and extension 498 to form a single element.

FIGS. 12S and 12T illustrate an expanding hole puncher 780, inaccordance with a preferred embodiment of the invention. FIG. 12S shownpuncher 780 in a compressed configuration and FIG. 12T shows puncher 780in an expanded configuration. In a preferred embodiment of theinvention, hole puncher 780 comprises an expanding tip 784 and anexpanding anvil 782. In a particular embodiment of the invention, tip784 is super-elastic, elastic or shape memory and is restrained fromexpanding by a tube 788. Once tube 788 is retracted, tip 784 expands,for example using an umbrella mechanism 790. Alternatively oradditionally, tip 784 is expanded using a balloon (not shown). Tip 784is preferably expanded after it pierces the blood vessel, however, itmay be expanded before too.

Anvil 782 preferably comprises a tube 782, which is maintained at acompressed diameter by an enclosing restraining tube 786. When tube 786is retracted, tube 782 expands, so that can be used as an anvil (or aknife edge or a scissors part) against the base of tip 784.

In a preferred embodiment of the invention, the hole puncher is removedby returning tube 788 and tube 786 to their original positions, therebycollapsing tip 784 and anvil 782. Alternatively or additionally, the tipand anvil may have a normally collapsed configuration, with theexpansion achieved, for example, by a balloon inserted in each of tip784 and anvil 782. When the balloons are deflated, the tip and anvilcollapse. Alternatively or additionally, other expansion/collapsingmechanisms may be used.

It should be appreciated that any of the above embodiments of holepunchers may be constructed to be expandable.

As indicated above, in some cases it is desirable to punch anoblique-profile hole and/or punch a hole for an oblique anastomosis. Ina preferred embodiment of the invention, the hole punching elementand/or the depressions thereon are made oblique. Alternatively oradditionally, the lips against which the element cuts are made oblique.Alternatively or additionally, the tissue stop for controlling theadvance of the hole puncher into the blood vessel is made oblique.

The hole formed by the hole puncher (or by other means) is preferablysmooth, for example being circular or elliptical. Alternatively, adifferent convex shaped hole, such as a triangle or higher-order polygonmay be cut. Alternatively, a concave hole may be cut, for example, acircular hole with a sine-wave variation on its circumference.Alternatively or additionally, a partial amount of vessel tissue may beremoved surrounding the hole, for example, so that the hole has asloping rim at least along some of its circumference. Alternatively oradditionally, such selective tissue removal is used to weaken the bloodvessel and/or to prevent tearing and/or to guide stress formed by theanastomosis.

The above description of a graft application kit is only exemplary andmany variations will occur to a man of the art, for example, the use ofother restraining mechanisms or other releasable fixing mechanisms toreplace the pin-mechanisms suggested.

In a preferred embodiment of the invention, the graft application kit ismade flexible, for use through an endoscope and/or a catheter or madeelongated, for use through in key-hole surgery. Preferably, thereleasing mechanisms are remotely operated, for example using pullwires. Alternatively or additionally, the springs are replaced by wireswhich are connected to springs outside the body.

FIGS. 13A–D illustrate a method of separately providing an anastomoticconnector 664 and a graft 38, at an anastomosis site, in accordance witha preferred embodiment of the invention. In FIG. 13A, a graft 38 isshown, which is urged against lips of a hole in aorta 30, by endoscope306, possibly, by an expanded portion 666 thereon. Thereafter, aconnector provision assembly 656 is advanced along endoscope 306. In apreferred embodiment of the invention, assembly 656 comprises an impalerbase 660 on which a plurality of impaler tubes 662 are mounted. In eachtube, a spike of connector 664 is provided. Alternatively, each tubeholds an individual staple. Alternatively, the tubes 662 are replaced bya hollow cylinder, inside which connector 664 is maintained in aflattened condition. The staples are coupled to an advancer 658.

In FIG. 13B, the ends of graft 38 are impaled by impaler tubes 662 andadvancer 658 is advanced relative to impaler base 660, so that the tipsof the staple extend, and bend to engage the walls of aorta 30.Preferably, the staples are elastic, super-elastic or shape-memory.

In FIG. 13C, both base 660 and advancer 558 are retracted, so that theother side of the staples are decoupled from advancer 558 and also bend,to engage graft 38 and/or aorta 30.

In an alternative embodiment shown in FIG. 13D, graft 38 is not cut tosize prior to insertion of the anastomosis device. Preferably, a largerexpanded portion 668 is formed in endoscope 302, such that tubes 662 areguided by portion 668 to engage graft 68 substantially perpendicularthereto. Additionally, graft 38 is at least partially everted by portion668. Once graft 38 is engaged by tubes 662, the rest of graft 38 may becut off, for example using a cutter (not shown). Alternatively oradditionally, expanded portion 668 is deflated and tubes 662 and graft38 are advanced into the aorta, as shown in FIG. 13B. Alternatively toan expanded portion, 668, a balloon or a different framework may beused.

FIGS. 14A–D illustrate a method of cutting a graft to size, during ananastomosis process in accordance with a preferred embodiment of theinvention. In FIG. 14A, an endoscope/guiding catheter 674 is used toform a hole in aorta 30 and place a connector 670 in the hole. In FIG.14B, the attachment of connector 670 to the aorta is completed.Thereafter, various activities may be performed through the connector,preferably using catheter 674. In FIG. 14C, a graft 38 is providedthrough catheter 674, attached to a far anastomosis and then thecatheter is retracted. In FIG. 14D, a plurality of spikes 676 inconnector 670 extend and engage the graft. Preferably, this extension isa result of the release of a constraint of catheter 674. Alternatively,a balloon or other expandable element (not shown) is expanded inconnector 670. The excess portion of graft 38 is then removed, forexample using a cutting tool 672 which cuts the graft against the insideof catheter 674. Possibly, one or more of spikes 676 may fold fromoutside the connector in, for example as shown by reference number 677.Preferably, the graft is urged against the inner surface of catheter 674by an inner element or a balloon, which balloon may also deflect suchspikes.

It should be appreciated that imaging devices may be used to track theprocess of anastomosis, including, the location, the quality of the sealand the relative positions of the tools, grafts and/or connectors. Suchimaging devices may be external to the body, internal to the body and/orprovided at catheter 34, such as near tip 37. Possible imaging devicesinclude: optical sensors, ultrasound sensors, fluoroscopy, open MRI andCT.

In many of the above described embodiments a balloon is suggested whendescribing an inflatable member. It should be appreciated that in manyembodiments what is required is a framework which can controllablychange its configuration, radially or axial, and/or possibly to applyforce. In some cases, a continuous surface is required, in others, onlythe relative positions of certain points on the balloon are important.Other framework types besides balloons are known to provide one or moreof these properties and may be used in the above described preferredembodiments of the invention. In some cases, these frameworks will becovered with a flexible covering, to reduce the danger of clottingand/or are removed after use.

The above description stresses CABG procedures and especially theaorta-to-graft anastomosis. However., it should be noted that many othertypes of blood vessels and/or grafts may be connected using the methodsdescribed herein. In one example, instead of connecting to the aorta,the anastomosis may originate from the descending aorta, from the LIMAor the RIMA or from other secondary blood vessels. In particular, in theLIMA, RIMA and other vessels which supply areas having a corollary bloodsupply, the vessel itself may serve as the graft which is navigated tothe clogged artery. Preferably, the vessel is blocked, for example usingsuturing or an expanding balloon, prior to being severed and navigated.Alternatively, the graft is exited from the severed end of the vessel,rather than from its side. In addition, although many examples aredescribed regarding the aorta, they are equally applicable to otherblood vessel. Also, it is noted that some of the above describedprocedures can be applied to the backside of the heart, which is notdirectly accessible from the chest.

Alternatively or additionally, blood vessels in other parts of the bodymay be bypassed, for example in the brain. Typically, bypass operationsin the brain are not performed for fear of damaging sensitive brainstructures. In a preferred embodiment of the invention, a graft isnavigated from a source vessel (such as the external or internalcarotid), through cavities which exist in the brain, to a cloggedvessel, past its occlusion. Possibly, a small part of this travel willbe through brain tissue. However, only a minimum of brain tissue need tobe damaged. Alternatively, the travel is through brain tissue which isknown to be less important, for example, by performing the procedurewhile the patient is awake and exciting the tissue to determineresponses from the patient. Preferably, this procedure is performedusing real-time imaging. Alternatively or additionally, an image guidedsystem, preferably incorporating a position sensor at the tip of thegraft, is used. Typically, the connectors, grafts and/or insertiondevices are smaller and/or more flexible when used for brain vascularsurgery than for vessels in the trunk, such as coronary vessels.

It should be appreciated that many of the structures described hereinmay also be applied to other invasive and/or implantable devices, beyondthose used for anastomosis, especially such devices which areinflatable, expandable and/or otherwise deployed. However, as will beappreciated, that some of the above described structures solveparticular problems of anastomosis, for example the problems ofcoordination between several actions, controllability and operationacross the vessel wall.

It will be appreciated that the above described methods of vascularsurgery may be varied in many ways, including, changing the order ofsteps, which steps are performed inside the body and which outside, theorder of making the anastomosis connections, the order of steps insideeach anastomosis, the exact materials used for the anastomoticconnectors and/or which vessel is a “side” side and which vessel (orgraft) is an “end” side of an end-to-side anastomosis. In addition, amultiplicity of various features, both of method and of devices havebeen described. It should be appreciated that different features may becombined in different ways. In particular, not all the features shownabove in a particular embodiment are necessary in every similarpreferred embodiment of the invention. Further, combinations of theabove features are also considered to be within the scope of somepreferred embodiments of the invention. Also within the scope of theinvention are surgical kits which include sets of medical devicessuitable for making a single or a small number of anastomosisconnections. When used in the following claims, the terms “comprises”,“comprising”, “includes”, “including” or the like means “including butnot limited to”.

It will be appreciated by a person skilled in the art that the presentinvention is not limited by what has thus far been described. Rather,the scope of the present invention is limited only by the followingclaims.

1. A method of providing a connector to a blood vessel, comprising:providing a distal end of a hole puncher adjacent a blood vessel;punching a hole in the blood vessel, by the hole puncher; transporting aconnector including at least one spike for attaching to the blood vesselthrough a lumen of the hole puncher, while the distal end of the holepuncher is adjacent the blood vessel; and engaging the blood vesselpunched by the hole puncher, by the at least one spike, whereintransporting the connector through the lumen comprises transporting theconnector from a proximal end of the hole puncher to the distal end ofthe hole puncher.
 2. A method according to claim 1, wherein providingthe distal end of the hole puncher adjacent the blood vessel comprisespressing the hole puncher against an outer wall of the blood vessel. 3.A method according to claim 1, comprising removing a sub-assembly of thehole puncher from a channel of the hole puncher, while the hole puncheris adjacent the blood vessel and transporting the connector through thechannel from which the subassembly was removed.
 4. A method according toclaim 3, wherein removing the sub-assembly comprises removing a centralcutter and a surrounding sheath.
 5. A method according to claim 3,wherein removing the sub-assembly comprises removing a central cutterwhile a surrounding sheath, that participated in the punching of thehole, remains with an end adjacent the blood vessel.
 6. A methodaccording to claim 1, wherein transporting the connector through thelumen is performed while the hole puncher is in contact with the bloodvessel.
 7. A method of treating a blood vessel, comprising: providing ahole puncher, including a tissue engager and a surrounding sheath,adjacent a blood vessel; punching a hole in the blood vessel by the holepuncher, utilizing the surrounding sheath; removing the tissue engagerfrom a channel of the hole puncher, while the surrounding sheath,utilized in the punching, remains in the vicinity of the blood vessel;and transporting a tool other than the tissue engager through thechannel, to the vicinity of the blood vessel.
 8. A method according toclaim 7, wherein the tool other than the tissue engager comprises aconnector.
 9. A method according to claim 8, wherein the connectorcomprises at least one spike.
 10. A method according to claim 7, whereinpunching the hole is performed utilizing both the tissue engager and thesurrounding sheath.
 11. A method according to claim 7, wherein thetissue engager includes an indent adapted to engage a wall of the bloodvessel.
 12. A method according to claim 7, wherein the tissue engagerhas a sharp distal end adapted to penetrate a hole in the blood vessel.13. A method according to claim 7, wherein the tissue engager isrotatable while being adjacent the blood vessel.
 14. A method accordingto claim 13, wherein the tissue engager is rotatable relative to theouter sheath, while being adjacent the blood vessel.
 15. A methodaccording to claim 7, wherein the tissue engager is adapted to bevibrated while being adjacent the blood vessel.
 16. A method accordingto claim 7, wherein punching a hole in the blood vessel comprisesrotating the tissue engager adjacent the blood vessel.
 17. A methodaccording to claim 16, wherein punching a hole in the blood vesselcomprises rotating the tissue engager, relative to the outer sheath,adjacent the blood vessel.
 18. A method according to claim 7, whereinpunching a hole in the blood vessel comprises vibrating the tissueengager adjacent the blood vessel.
 19. A method according to claim 7,wherein transporting the tool through the channel comprises transportingthe tool through the channel after removing the tissue engager from thechannel.